Chromatographic behavior of six lanthanides on a centrifugal mixer-settler extractor cascade.

This work furthers the development of counter-current chromatography as an industrial separation process method. It was demonstrated that the industrial counter-current chromatography methods, in particular, for the separation groups of rare earth metals, can be implemented in a modified cascade of centrifugal mixer-settler extractors. The retention behavior of rare earth elements (samarium, europium, gadolinium, terbium, dysprosium and yttrium) on the pilot chromatographic unit consisting of 70 serially connected centrifugal mixer-settler extractors was experimentally studied under isocratic elution conditions using the mixture of 30 vol.% CyanexⓇ572 + 10 vol.% tributylphosphate in a hydrocarbon diluent as the stationary phase and aqueous nitric acid as the mobile phase. Theoretical analysis of experimental studies showed an acceptable agreement between the assumptions of the theory and experimental results.

Molecularly imprinted sensor based on Russian Matryoshka structured molecules for enhanced specific identification and double amplification in ultra-trace Tb3+ determination.

The selective and sensitive detection of rare earth elements is thought to be difficult because the concentration of those elements in the sample is commonly at a low level and they normally have severe mutual interference which is caused by homologous chemical properties. In this study, a novel molecularly imprinted polymer (MIP) sensor was fabricated for highly sensitive and selective determination of ultra-trace Tb3+. The Tb3+-ethylenediaminetetraacetic acid complex (Tb-EDTA) as the template molecule was incorporated into mono-6-mercapto-ß-cyclodextrin (mono-6-SH-ß-CD) to form a Russian Matryoshka (RM)-structured molecule (CD/Tb-EDTA). Titanium isopropoxide was utilized in vapor sol-gel polymerization to construct MIP membrane. Moreover, the selectivity of the RM MIP sensor was remarkably enhanced by the "triple-selectivity" recognition of EDTA-to-Tb3+, ß-CD-to-(Tb-EDTA), and 3D cavity-to-(CD/Tb-EDTA), while the sensitivity of the MIP sensor was significantly improved by ECL signal enhancement based on double amplification, in other words, the electrochemiluminescence resonance energy transfer (ECL-RET) between the ECL donor of CD/Tb-EDTA and the ECL acceptor of Ru(bpy)32+, and the ECL enhancement by the co-reactant of CD/Tb-EDTA on Ru(bpy)3Cl2. When the imprinted cavities were occupied by Tb-EDTA during rebinding, the host-guest inclusion structured complex was formed and the ECL intensities produced by the Ru(bpy)3Cl2 ECL system increased with increasing concentration of Tb-EDTA. The proposed sensor was used for quantitative analysis of Tb3+ with concentrations ranging from 8.00 × 10-13 mol/L to 4.00 × 10-9 mol/L and successfully applied to detect Tb3+ in seawater samples. The detection limit of the sensor was found to be 3.90 × 10-13 mol/L (DL = 3δb/K), which is lower than previously reported values. Thus, the fabricated sensor is feasible for practical applications.

The low-energy ß(-) and electron emitter (161)Tb as an alternative to (177)Lu for targeted radionuclide therapy.

INTRODUCTION: The low-energy ß(-) emitter (161)Tb is very similar to (177)Lu with respect to half-life, beta energy and chemical properties. However, (161)Tb also emits a significant amount of conversion and Auger electrons. Greater therapeutic effect can therefore be expected in comparison to (177)Lu. It also emits low-energy photons that are useful for gamma camera imaging. METHODS: The (160)Gd(n,γ)(161)Gd→(161)Tb production route was used to produce (161)Tb by neutron irradiation of massive (160)Gd targets (up to 40 mg) in nuclear reactors. A semiautomated procedure based on cation exchange chromatography was developed and applied to isolate no carrier added (n.c.a.) (161)Tb from the bulk of the (160)Gd target and from its stable decay product (161)Dy. (161)Tb was used for radiolabeling DOTA-Tyr3-octreotate; the radiolabeling profile was compared to the commercially available n.c.a. (177)Lu. A (161)Tb Derenzo phantom was imaged using a small-animal single-photon emission computed tomography camera. RESULTS: Up to 15 GBq of (161)Tb was produced by long-term irradiation of Gd targets. Using a cation exchange resin, we obtained 80%-90% of the available (161)Tb with high specific activity, radionuclide and chemical purity and in quantities sufficient for therapeutic applications. The (161)Tb obtained was of the quality required to prepare (161)Tb-DOTA-Tyr3-octreotate. CONCLUSIONS: We were able to produce (161)Tb in n.c.a. form by irradiating highly enriched (160)Gd targets; it can be obtained in the quantity and quality required for the preparation of (161)Tb-labeled therapeutic agents.

Separation of carrier free 151,152Tb produced in 16O irradiated lanthanum oxide matrix.

Charged particle activation of natural La2O3 with approximately 78.5 MeV 16O results in the formation of carrier free 151,152Tb isotopes in the matrix. The liquid cation exchanger, HDEHP, has effectively been utilised as an extractant in the quantitative separation of the activation products from the bulk target matrix of lanthanum oxide.