Highly Promising Method for the Decontamination of Europium from Americium Using an Extraction Chromatography Resin Containing a Tripodal Diglycolamide and SO₃Ph-BTP as Eluent

Separation of Am3+ from Eu3+ was demonstrated by extraction column chromatography using a tripodal diglycolamide ligand (T-DGA). A clean separation was achieved by selective complexation of Am3+ in the feed with 2,6-bis(5,6-di(sulfophenyl)-1,2,4-triazin-3-yl)pyridine (SO3Ph-BTP) with a separation factor of about 2000. The extraction chromatography resin material with particle size in the range of 175-250 μm contained only 7.4% T-DGA ligand (53 μmol/g) and is one of the most efficient materials used for this purpose until date. Parameters such as feed acidity and SO3Ph-BTP concentration were varied, while keeping the other parameters constant for getting the best optimized condition for the separation of Am3+ from Eu3+ ions. The optimized feed condition was 0.1 M HNO3 containing 10 mM SO3Ph-BTP for the clean separation of Am3+ from the Eu3+ fraction. In the feed solution containing Eu3+ and Am3+, the latter was complexed with SO3Ph-BTP and, therefore, was not retained on the column, whereas the uncomplexed Eu3+ could be efficiently held onto the column. Finally, the loaded Eu3+ from the column was eluted with 0.1 M HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid), giving a sharp and narrow elution curve. The radiation stability of the resin was excellent up to 1000 KGy gamma dose, and an identical separation efficiency of the resin was noted with the irradiated resin column, as was obtained with the pristine resin.</p

Solvent systems containing diglycolamide-functionalized calix[4]arenes in room temperature ionic liquid for metal ion extraction: studies with simulated high-level wastes

The extraction of actinide ions such as Am(III), Pu(IV), Np(IV), U(VI) and Pu(VI) was studied from simulated high-level waste (SHLW) solutions using several diglycolamide-functionalised calix[4]arene (Calix-DGA) ligands dissolved in the room temperature ionic liquid (RTIL) [C8mim][NTf2]. The Calix-DGA ligands were three lower-rim functionalised ligands with varying alkyl substituents (L-I, L-II and L-III), an upper-rim functionalised ligand (L-IV) and an upper- and lower-rim functionalised ligand (L-V). The SHLW solutions used contained 0.5 M HNO3 and the extraction trend of the actinides was found out to be Am(III) > Pu(IV)∼Np(IV)≫ and the extraction efficiency of the Calix-DGA ligands for Am(III) being L-V>L-I>L-II>L-IV>L-III. Reasonably, good extraction of Am(III) was obtained with 5.0 × 10− 4 M ligand solutions suggesting that higher concentrations of the ligand can be used for a higher loading of the metal ions. The extraction of other metal ions representing fission products, structural materials and process chemicals was studied by Inductively Coupled Plasma –Atomic Emission Spectroscopy analysis. The extraction mechanism follows the cation-exchange mechanism often observed with RTIL-based extraction systems. Enthalpy changes were measured from van't Hoff plots and were found to be significantly different than those observed with tracer studies reported previously

A highly efficient sensor for europium(III) estimation using a poly(propylene imine) diaminobutane diglycolamide dendrimer as the ionophore:Potentiometric and photoluminescence studies

Multiple-diglycolamide (DGA) based ligands are known as highly promising extractants for the selective and efficient extraction of trivalent lanthanides/actinides from acidic feed solutions and therefore they have a great potential for the low level detection of these metal ions when used as ionophores in a potentiometric sensor. However, their use as ionophores in a potentiometric sensor is not much explored. Here in, we report the potentiometric sensing of Eu(III) ion in acidic medium using three novel multiple DGA-functionalized dendrimers: viz., generation zero (G0), one (G1) and two (G2) poly(propylene imine) diaminobutane dendrimers as ionophores doped in a polyvinyl chloride (PVC) matrix containing 2-nitrophenyl octyl ether (NPOE) as the plasticizer and sodium tetraphenylborate (NaTPB) as the ionic additive. Out of these three dendrimers, the G1 membrane gave very encouraging results and the G2 membrane did not work properly. On the other hand, the G0 membrane showed a narrower linear dynamic range (LDR), and a higher limit of detection (LOD) than the G1 membrane. The membrane with 4.1 % G1, 31.1 % PVC, 62.2 % NPOE, 2.6 % NaTPB exhibited a linear response behaviour from 6.6 × 10-7 M to 1.5 × 10-2 M Eu(III) with a slope of 15.6 ± 0.2 mV/decade and a LOD of 5.0 × 10-7 M. The response time and lifetime of this sensor were found to be &lt; 10 s and more than three months, respectively, and showed reasonably high selectivity with respect to mono- and divalent cations as well as the uranyl ion. All the sensor membranes contained two types of Eu(III) species as seen by luminescence spectroscopy. The sensor efficiency was checked by the ‘spike recovery method’. The G1 membrane sensor was also employed for the potentiometric titration of Eu(III) as an indicator electrode. Both methods showed more than 95 % recovery with excellent matching with the X-ray fluorescence (XRF) results. The sensor can also be used in the estimation of europium ion in a laboratory bearing waste and in a lamp phosphor waste leached which compared well with XRF and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) results, respectively.</p