DTPA Solution Research Articles

225Aс/213Bi generator for direct synthesis of 213Bi-labeled bioconjugates

Background213Bi is a short-lived radionuclide currently trialed for alpha therapy of various oncological diseases. A serious obstacle to the wide medical use is decay losses of 213Bi during a conventional synthesis of radiopharmaceuticals. In this work, we aimed to develop a two-column 225Aс/213Bi generator providing the accumulation of 213Bi separately from the parent 225Ac via continuous circular separation and decay of intermediate 221Fr. When attaining the transient equilibrium, 213Bi could be promptly extracted from the generator with an appropriate complexing agent, including chelator-protein bioconjugates. MethodsSorption behavior of Bi(III) ions onto the cross-linked dextran gel Sephadex G-25 was studied from solutions of hydrochloric and nitric acid, and from sodium chloride, sodium acetate and DTPA solutions. A bifunctional chelating agent p-SCN-Bn-DTPA was conjugated to an antibody Nimotuzumab specific to the epidermal growth factor receptor, and the procedure of 207,213Bi-DTPA-Nimotuzumab synthesis in the dextran gel medium was developed. The parameters of 225Aс/213Bi generator system were evaluated. ResultsThe weight distribution ratios of Bi(III) adsorbed onto the Sephadex G-25 gel were obtained. Up to 85 % of 213Bi was accumulated in the second Sephadex-filled column of 225Aс/213Bi generator after four-hour circulation of 0.15 M NaCl (pH 5.5) solution. Having passed the solution of DTPA-Nimotuzumab bioconjugate through the second column, a fraction of 213Bi-DTPA-Nimotuzumab radioimmunoconjugate was produced with the radiochemical yield of 64 % ± 3 % (n = 6). High radionuclidic and radiochemical purity of product was achieved. ConclusionsThe circulating 225Aс/213Bi generator provides a 213Bi-labeled bioconjugate as a final product. While a conventional synthesis route including generator milking, bioconjugate labeling and size-exclusion purification takes >20 min, the duration of 213Bi-DTPA-Nimotuzumab production by the method proposed in this work is reduced to 6–8 min.

Use of Cannabis sativa L. for Improving Cadmium-Contaminated Mediterranean Soils—Effect of Mycorrhizal Colonization on Phytoremediation Capacity

Although the phytoremediation strategy has been studied worldwide, little research data are available regarding the influence of mycorrhizae on the phytoremediation capacity of various plants grown in Cd-contaminated soils in Mediterranean environments. Therefore, a pot experiment was carried out to study the possible effectiveness of hemp plant (Cannabis sativa L.) in the remediation of moderately and heavily Cd-contaminated soils and additionally to quantify the effect of Cd on Arbuscular Mycorrhizal Fungi (AMFs). For this purpose, an alkaline clay soil collected from the Farm of Institute of Plant Breeding and Genetic Resources (North Greece) was contaminated with two levels of Cd (3 and 30 mg Cd kg−1, corresponding to Levels A and B, respectively—first factor) at two incubation times (10 and 30 days—second factor) and six treatments (Control_30d, Control_10d, CdA_30d, CdB_30d, CdA_10d, CdB_10d) were created. Soil Cd concentrations, both pseudo-total and available to plants, were determined after extraction with Aqua Regia mixture and DTPA solution, respectively, before and after the cultivation of hemp plants and after the harvesting. Cd concentrations in the aboveground and underground plant parts were also estimated after digestion with Aqua Regia, while root colonization by AMFs was determined with a microscope. The highest plant’s Cd concentration, more than 50%, was observed in its underground part, at all Cd-contaminated treatments, indicating a strong capacity for cadmium to gather up in the roots. Among different Cd levels and incubation days, significant differences were recorded in the rates of root colonization by AMFs. Among different Cd levels and incubation days, 3 mg Cd Kg−1 soil promoted AMF root colonization, particularly at 10-day incubation, while 30 mg Cd Kg−1 soil diminished it. Colonization was lower with longer incubation times at both levels of Cd. Hemp appears to be a viable option for phytostabilization in Cd-contaminated soils, enabling further utilization of AMFs to assist the phytoremediation process.

Effect of ionizing radiation on DTPA and NTA solutions containing rare-earth and transplutonium elements and nitric acid

Effect of ionizing radiation on DTPA and NTA solutions containing rare-earth and transplutonium elements and nitric acid

Rate of Microelement Quantitative Changes during the Composting of Sewage Sludge With Various Bulking Agents

The composting of sewage sludge (SS) with structure-forming additives is a popular and inexpensive method for the management of biodegradable waste. During this process, a number of transformations of organic matter and nutrients occur. This study presents the rates and directions of quantitative changes in Cu, Zn, and Ni during the composting of various mixtures. The following substances were used for preparing compost mixtures: SS, sawdust, straw, and bark. These substances were mixed together in appropriate proportions as follows: C1: 45% SS + 50% sawdust + 5% straw; C2: 45% SS + 50% bark+ 5% straw; and C3: 45% SS + 35% bark + 15% sawdust + 5% straw. Single (DTPA solution) and sequential extraction methods (BCR protocol) were used for microelement mobility assessment. Compost valorization was performed in each individual composting phase. The chain relative increment analysis was used for such assessment. Additionally, the potential metal pollution in the composts was evaluated by applying the following indices: the pollutant accumulation index (PAI), heavy metal enrichment index (HMEI), and heavy metal pollution load index (HMPLI). During composting, generally, the amounts of Ni, Cu, and Zn increased in the various extracted combinations, which was independent of their susceptibility to decomposition. Despite of this, the tested composts should be considered as a source of slowly available microelements for plants. The most intense quantitative changes in metals occurred in the thermophilic phase, and the weakest changes occurred in the cooling phase. At the same time, the calculated indices indicated a lack of contamination of the composts with the analyzed metals, emphasizing their environmental safety and lack of negative impact. The bulking agents used for composting with SS did not significantly influence the intensity of the quantitative changes in the tested metals.

Removal of some Heavy Metals from Industrial Wastewater and Gray Water by using some Natural and Organic Materials

A study was conducted for knowing the quantity and quality of heavy metal ions adsorbed on surfaces of treatment materials used in treatment of polluted water and to know the most efficient in removal process. Study included conducting two experiments, the first is laboratory, which is treatment of two polluted waters, namely industrial water and gray water, using four natural treatment materials as filters, which are activated Charcoal, Eichhornia crassipes plant powder, Ceratophyllum plant powder, and Arundo donax plant powder. It used poles made of polyethylene with a length of 100 cm and a diameter of 10 cm equipped with a tap from bottom, a layer of glass wool was placed at bottom, and then treatment materials were placed on top of it at a height of 50 cm. A piece of gauze cloth was placed over it for filtering polluted water from solids. Polluted water was passed after being filtered from top of column and left for 24 hours for equilibrium, then filtrate was collected from bottom of column. Second experiment, it is liberation experiment for heavy metals adsorbed on treated materials, where heavy metals were extracted by a 0.005M concentration of DTPA solution. This process was repeated five times for same treatment material and concentration of heavy metals adsorbed was measured each time. Results showed the following: 1-High concentrations of heavy metals, each of Lead, Cadmium, Zinc and Nickel in industrial water, where they reached 5.190, 0.043, 3.727 and 0.371 mg L-1, respectively, exceeding the limits allowed by World Food and Health Organization for each of Cadmium, Zinc and Nickel, while concentrations of Lead is within internationally permitted limits. As for the gray water, concentrations of Cadmium excelled the internationally permitted limits, while concentrations of Lead, Zinc and Nickel were within internationally permitted limits. 2-Concentration of Lead and Cadmium in all materials used in bioremediation, with exception of coal, exceeded internationally permitted limits in plants. Concentrations of Zinc and Nickel in all materials used in bioremediation did not exceed the internationally permitted limits, while coal did not record the presence of Zinc and Nickel because it is a porous, burned carbonaceous material. 3-Increasing amount of heavy metals liberated from various treatment materials through bioreclamation process in first three extractions, then it began to gradually decrease in fourth and fifth extractions. The different treatment materials varied in amount of heavy metals released, and they can be arranged as follows in terms of amount released of heavy metals: Eichhornia crassipes plant powder > Ceratophyllum plant powder > activated charcoal > Arundo donax plant powder. 4-Highest amount of heavy metals was released from materials used in industrial water, then gray water for Lead and Cadmium, while treatment materials used in industrial water and then gray water excelled in amount released for elements Zinc and Nickel.

Extraction of Cesium, Strontium, and Stable Simulated HLW Components with Substituted Crown Ethers in New Fluorinated Diluents

ABSTRACT The extraction of cesium, strontium, and a number of stable components of simulated high-level waste solutions from nitric acid media with solutions of crown ether derivatives in new fluorinated diluents was studied. Based on the data on the solubility of the extractants into the aqueous phase and the physicochemical properties of the diluents used, the most promising extraction systems were chosen: crown ethers 4,4‘(5’)-di-tert-butyldibenzo-18-crown-6 (L1) and 4,4‘(5’)-di-tert-butyldicyclohexyl-18-crown-6 (L2) in bis(2,2,3,3-tetrafluoropropyl) carbonate (BK-1) and bis(2,2,3,3-tetrafluoropropoxy)methane (FN-1). For these systems, the extraction of a number of stable components and their subsequent stripping with water and solutions of chelating agents were studied. Lead was found to be co-extracted to the greatest extent. To a lesser extent, barium and calcium cations are co-extracted with strontium, and rubidium and potassium cations with cesium. Lead, barium, and silver are the most difficult to strip; however, the problem of lead stripping can be solved by using DTPA or citric acid solutions neutralized with ammonia to weakly alkaline (pH 8) media.

Evaluation of Agricultural Value of Composts Prepared from Municipal Biowastes in Different Conditions of Composting Process

The increasing mass of organic waste as well as the assumptions of a circular economy enforce the rational management of this type of waste. One method of recycling is composting, which makes it possible to use waste efficiently as an organic fertilizer. This paper presents the results of a comparative study of six different composts in terms of their agricultural quality. The aim of this study was to evaluate the bioavailable amounts of metals using single extractions with DTPA solution and to characterize various humic compounds. Particular attention was paid to the amounts of labile carbon (LC), hot water-extractable carbon (HWC), and the quantity and quality of humus substances (HS). Regardless of compost types, they were characterized by a small share of easily decomposable compounds such as fulvic acids (FAs), LC, and HWC, which may indicate the low susceptibility of compost humic substances to microbiological degradation in soil. In general, the bioavailable metal amounts found in the analyzed composts were low; therefore, the tested composts applied to the soil can be considered safe for the environment.

Assessment of remediation of soils, moderately contaminated by potentially toxic metals, using different forms of carbon (charcoal, biochar, activated carbon). Impacts on contamination, metals availability and soil indices

The present study aims to assess the effect of three forms of carbon, i.e., charcoal, biochar and activated carbon using as soil amendments (or soil conditioners) in two soils, an acid and alkaline one. For this purpose, a pot experiment was conducted by mixing six sub-samples for each soil along with the three amendments in the appropriate proportion. Total, pseudo-total and available metal concentrations were determined. Moreover, the BCR fractionation method was applied and the four soil fractions were identified. A significant decrease in the concentrations of all four metals in the water-soluble and exchangeable fraction (F1) was observed. At the same time, a high reduction was observed in the available concentrations of metals as well, ie those that were extracted after using the DTPA solution. Soil indices were also used in order to monitor and evaluate the possible ecological risk and the effect in metal concentrations after the application of the amendments. The use of the studied materials can be very promising soil conditioners, as they can precisely, economically, time-effectively, and efficiently can remediate soils, moderately contaminated with toxic metals.

Kinetics of Nano-zinc Oxide in Desert Calcareous Soils

A laboratory experiment was carried out to study the kinetics reaction of zinc added to calcareous soils from different fertilizer sources and extracted by DTPA solution. Where two types of fertilizers were added, the first, nano-zinc fertilizers in the form of nano-metallic zinc oxide (ZnnO), nano-chelated zinc (ZnnDTPA), and nano-zinc humate (ZnnHA), while the second type was the same fertilizer sources, but in their regular form (ZnO, ZnDTPA and ZnHA). All of them were added at a concentration of 100 mg kg-1 and the nano and regular zinc sources were incubated after they were added to the soil to know their physical and chemical behavior during different incubation periods of 0, 5, 10, 20, 40, 80, 120 and 160 days, with two replications for each incubation period. After the end of each period, zinc was extracted by DTPA, and the data of extracted zinc were subjected to five kinetic equations to reach the best equation describing the behavior of zinc release. The results showed a rapid decrease in the concentration of zinc extracted at the incubation period of 0 days for all fertilizer sources and the continuation of the decrease in concentration with the length of the incubation period gradually until the end of the period after 160 days. The percentage of decrease in nano-zinc fertilizer was less than that of regular fertilizers. The ZnnDTPA chelated zinc source was superior among the regular and nano fertilizer in giving the highest concentration of zinc throughout the incubation period. The second-order equation was the most efficient in describing the behavior and reaction of zinc kinetics in soil from its different sources. The behavior and kinetics reaction of zinc in soil from its different sources.

The Effect of Compost and Fly Ash Treatment of Contaminated Soil on the Immobilisation and Bioavailability of Lead

The study discusses changes in lead contents in soil and crops after application of compost and fly ash. A three-year experiment was conducted on narrow-leaved lupine (Lupinus angustifolius L.), camelina (Camelina sativa L.) and oat (Avena sativa L.), which were grown on medium soil fertilised with compost or fly ash (FA). The lead amounts in various combinations were evaluated using sequential (BCR analysis) and single (DTPA solution) methods. The total contents of lead and amounts of selected macronutrients were assessed in the biomass of plants. The Pb contents in the soil and plants were used to calculate the risk assessment code (RAC), individual contamination factor (ICF), bioconcentration factor (BCF) and contamination coefficient level (CCL). Lower amounts of bioavailable Pb in the soil were observed as a result of compost and FA application. Fly ash immobilised Pb more effectively, as evidenced by the BCF and CCL values. The increase in the Pb contents in the sequentially separated fractions and in plant biomass were caused by applied compost or FA. The Pb contents in exchangeable forms decreased, whereas its contents in residual forms increased.

Adsorption and separation behaviors of Y(III) and Sr(II) in acid solution by a porous silica based adsorbent

Aiming at selective adsorption and separation of Y(III) from the Y(III)–Sr(II) group in acid solution, a silica-based TODGA impregnated adsorbent [(TODGA+1-dodecanol)/SiO2–P–F600] has been prepared. Batch adsorption experiments were conducted under the effect of contact time, acid concentration, solution temperature, and adsorption capacity etc. Chromatography recovery of more than 90% Y(III) was successfully achieved under elution with 0.01 M DTPA solution in nitric acid adsorption system, and 0.1 M HCl solution in hydrochloride adsorption system, respectively.

68Ga, 44Sc and 177Lu-labeled AAZTA5-PSMA-617: synthesis, radiolabeling, stability and cell binding compared to DOTA-PSMA-617 analogues

BackgroundThe AAZTA chelator and in particular its bifunctional derivative AAZTA5 was recently investigated to demonstrate unique capabilities to complex diagnostic and therapeutic trivalent radiometals under mild conditions. This study presents a comparison of 68Ga, 44Sc and 177Lu-labeled AAZTA5-PSMA-617 with DOTA-PSMA-617 analogues. We evaluated the radiolabeling characteristics, in vitro stability of the radiolabeled compounds and evaluated their binding affinity and internalization behavior on LNCaP tumor cells in direct comparison to the radiolabeled DOTA-conjugated PSMA-617 analogs.ResultsAAZTA5 was synthesized in a five-step synthesis and coupled to the PSMA-617 backbone on solid phase. Radiochemical evaluation of AAZTA5-PSMA-617 with 68Ga, 44Sc and 177Lu achieved quantitative radiolabeling of > 99% after less than 5 min at room temperature. Stabilities against human serum, PBS buffer and EDTA and DTPA solutions were analyzed. While there was a small degradation of the 68Ga complex over 2 h in human serum, PBS and EDTA/DTPA, the 44Sc and 177Lu complexes were stable at 2 h and remained stable over 8 h and 1 day. For all three compounds, i.e. [natGa]Ga-AAZTA5-PSMA-617, [natSc]Sc-AAZTA5-PSMA-617 and [natLu]Lu-AAZTA5-PSMA-617, in vitro studies on PSMA-positive LNCaP cells were performed in direct comparison to radiolabeled DOTA-PSMA-617 yielding the corresponding inhibition constants (Ki). Ki values were in the range of 8–31 nM values which correspond with those of [natGa]Ga-DOTA-PSMA-617, [natSc]Sc-DOTA-PSMA-617 and [natLu]Lu-DOTA-PSMA-617, i.e. 5–7 nM, respectively. Internalization studies demonstrated cellular membrane to internalization ratios for the radiolabeled 68Ga, 44Sc and 177Lu-AAZTA5-PSMA-617 tracers (13–20%IA/106 cells) in the same range as the ones of the three radiolabeled DOTA-PSMA-617 tracers (17–20%IA/106 cells) in the same assay.ConclusionsThe AAZTA5-PSMA-617 structure proved fast and quantitative radiolabeling with all three radiometal complexes at room temperature, excellent stability with 44Sc, very high stability with 177Lu and medium stability with 68Ga in human serum, PBS and EDTA/DTPA solutions. All three AAZTA5-PSMA-617 tracers showed binding affinities and internalization ratios in LNCaP cells comparable with that of radiolabeled DOTA-PSMA-617 analogues. Therefore, the exchange of the chelator DOTA with AAZTA5 within the PSMA-617 binding motif has no negative influence on in vitro LNCaP cell binding characteristics. In combination with the faster and milder radiolabeling features, AAZTA5-PSMA-617 thus demonstrates promising potential for in vivo application for theranostics of prostate cancer.

Availability of Nickel in Soil Evaluated by Various Chemical Extractants and Plant Accumulation

This work presents quantitative changes of nickel in soil and plants under the influence of compost and fly ash. The research was carried out in a 3-year experiment on medium soil fertilised with compost or fly ash. The plants: narrow leaf lupine (Lupinus angustifolius L.), camelina (Camelina sativa L.), and oat (Avena sativa L.) were planted in consecutive years. The soil from the experiment was subjected to extraction by sequential analysis with the Community Bureau of Reference (BCR) method, and single extractions using 1 mol·dm−3 HCl and DTPA solutions, obtaining the amount of nickel in various combinations with the soil solid phase. Total contents of the metal in soil and cultivated plants were determined. On the basis of Ni contents in the soil and cultivated plants, the bioconcentration factors and the risk assessment code were calculated. The type of amendments had a significant impact on the nickel content in lupine, for camelina and oat was the greatest in the control conditions. The differences between the amounts of Ni determined for bioconcentration factors were significant and depended on the amendments and nickel obtained by different methods. Regardless of the experimental conditions, the amount of Ni in the exchangeable bonds (Fr. I) had the greatest impact on the content of Ni in lupine and oat, whereas NiDTPA in the case of camelina.

The Development of a Model for Recommending the Application of Zinc Fertilizer in the Mediterranean Region of Central Chile

The main aim of this study is to develop a mechanistic model of fertilization for recommending the application of zinc (Zn) fertiliser for maize based on the mass balance of Zn. The model would consider the critical Zn level for maize (ZnCL), Zn availability in the soil (ZnA) and Zn buffering capacity (Znb). Soil samples were collected from 78 maize fields for chemical and physical characterization including measuring ZnA and Znb. Additionally, a crop management survey was carried out in each field. The classification and regression trees method (CART) was used and relationships between Znb and some soil properties were established, clay content being the most relevant to the model, besides soil reaction (pH) and silt content. The application of Zn fertilizer can be adequately calculated by a mechanistic model that considers ZnA, Znb and ZnCL above that which maize crop yields do not increase. This work highlights the importance of Znb evaluation by the incubation procedure and the extraction of available Zn by DTPA solution. As hypothesised and then demonstrated in this work, Znb is closely related to soil pH and texture (clay and silt). Our results suggest that, in between 51 and 97% of fields examined, it would be necessary to apply Zn fertilisers to produce the maximum maize yield.

All-chromatographic method for the recovery of Americium-241 from solutions of complex composition

This paper reported creating the all-chromatographic technique for the recovery of americium radionuclides from solutions of the complex composition generated in the radiochemical industry. The technique was based entirely on the displacement complexing chromatography; neither additional precipitation nor extraction stages were necessary. The technology used the elution with DTPA and NTA-based solutions containing the citric acid additives and the sequential elution with these eluents, emphasizing the separation of americium from the heavy rare earth elements, lead, and cadmium. The complete separation of americium from lead and cadmium was a peculiar exercise; the elution order of lead and cadmium changed in the presence of the citric acid additives. The recovery and separation of americium from actual radioactive waste solutions of different origins demonstrated 96 and 99% chemical purity of the final product.

Biochar and bacteria inoculated biochar enhanced Cd and Cu immobilization and enzymatic activity in a polluted soil

The application of biochar in the remediation of heavy metal contaminated soil has received increasing global attention during the past decade. Although there has been some review work on the mechanism of heavy metals stabilization by biochar, the effects and mechanisms of interaction between biochar and functional microbes such as heavy metal tolerant, adsorption and transformation microbial strains remains unclear. In this paper, maize biochar and a heavy metal-tolerant strain Pseudomonas sp. NT-2 were selected to investigate the dynamic effects and potential mechanisms of biochar and bacteria loaded biochar on the stabilization of Cd and Cu mixed contaminated soil by a 75-day pot experiment. The results showed that, compared to the single biochar amendment, the application of biochar inoculated with NT-2 strain at the rate of 5% significantly increased the soil pH at the initial stage of incubation, and followed by a slight decline to a neutral-alkaline range during the reaction. The addition of NT-2 loaded biochar could also significantly increase the proportion of residual fraction of Cd and Cu, thus reduce the proportion of exchangeable and carbonate bound species in the soil, which lead to the decreasing of plant and human bioavailability of the metal in the soil indicated by DTPA and simulated human gastric solution extraction (UBM), respectively. Finally, the application of bacterial loaded biochar also markedly enhanced soil urease and catalase activities during the later stage of the incubation, and improved soil microbial community at the end of incubation, which indicates a recovery of soil function after the metal stabilization. The research results may provide some new insights into the development of functional materials and technologies for the green and sustainable remediation of heavy metal contaminated soil by the combination of biochar and functional microorganisms.

99mTc-68Ga-ICG-Labelled Macroaggregates and Nanocolloids of Human Serum Albumin: Synthesis Procedures of a Trimodal Imaging Agent Using Commercial Kits.

Recent developments in sentinel lymph node (SLN) and radio occult lesion localization (ROLL) highlight the need for a multimodal contrast agent, providing better presurgical PET imaging and improved intraoperative mapping thanks to fluorescence detection. For this reason, we have studied a trimodal SLN/ROLL targeting agent (99mTc-68Ga-ICG) with commercially available kits of macroaggregated or nanocolloidal albumin (MA/NC-HSA). 68Ga PET imaging does provide better spatial resolution and makes it possible to predict signal intensity during surgery. The presence of 99mTc assesses the efficacy of these compounds in vitro and also during the surgery procedure. The aim of this study was to optimise the labelling and tagging of these two radiopharmaceuticals and assess their yields and stability. Kits of MA/NC-HSA particles (Pulmocis® and NanoAlbumon®) were used for sequential radiolabelling with 99mTc and 68Ga. Fluorescent tagging was performed using indocyanine green, a tricarbocyanine dye. The ITLC radiochemical purity of the trilabelled MA/NC-HSA was >95%. Fluorescent purity was measured by scanning the strips with a PhotoDynamicEye probe. Finally, in vitro stability tests, performed with DTPA and human serum solutions, assessed the efficacy of fluorescent tagging and radiolabelling.

Chelation Treatment by Early Inhalation of Liquid Aerosol DTPA for Removing Plutonium after Rat Lung Contamination.

Occupational contamination is a potential health risk associated with plutonium inhalation. DTPA remains the chelating drug of choice to decorporate plutonium. In this study, plutonium was found to be more effectively removed from lungs by a single inhalation of nebulized DTPA solution at only 1.1 µmol.kg-1 than by a single intravenous (i.v.) dose of DTPA at 15 µmol.kg-1. When DTPA was inhaled promptly after contamination, it removed the transportable fraction of plutonium prior blood absorption, thereby preventing both liver and bone depositions. Conversely, DTPA injection was better than inhalation at reducing the extrapulmonary burden, probably due to the much greater circulating dose, favoring the mobilization of plutonium already translocated. Thus, prompt inhalation, concomitantly supplemented with i.v. injection, of DTPA induced an important decrease in extrapulmonary deposits. Repeated DTPA inhalations over several weeks were more efficient than a single inhalation in limiting both pulmonary and extrapulmonary plutonium retention, due at least in part to the chelation of the transportable fraction of lung plutonium. Furthermore, repeated DTPA injections remained better at reducing liver and bone plutonium retentions. Taken together, our results suggest that multiple DTPA inhalations may be considered an effective treatment after inhalation of plutonium, particularly given the ease of this needle-free delivery, for the two following conditions: 1. A treatment combining i.v. injection and inhalation should be given in an emergency scenario to efficiently chelate the activity already absorbed; 2. Inhalations should be administered daily to effectively trap the early transferable fraction.

Isolation of Plutonium in the Course of REE/TPE Separation by Displacement Complexing Chromatography

Isolation of Pu from a TPE/REE mixture by displacement complexing chromatography on KU-2 cation-exchange resin was studied. To stabilize Pu in the trivalent state, the sorption of the mixture components from the initial solutions was performed in the presence of hydrazine nitrate. To convert Pu to the tetravalent state, H2O2 was added to the DTPA solution used as an eluent. The influence of temperature and H2O2 concentration on the chromatographic isolation of Pu was studied. Optimum conditions were found for separating Pu from TPE and REE.

Extraction of actinide ions using three CMPO-functionalized pillar[5]arenes in a room temperature ionic liquid

Abstract Extraction of actinide ions from nitric acid feeds was investigated using solutions of three CMPO (carbamoyl methyl phosphine oxide) functionalized pillar[5]arenes with varying spacer lengths in a room temperature ionic liquid, [C8mim][NTf2]. The extraction of Am3+ was found to decrease with increasing nitric acid concentration suggesting a mechanism analogous to a cation-exchange mechanism. The nature of the extracted species was determined by the conventional slope analysis method to be ML type which was subsequently confirmed by luminescence spectroscopy. Studies carried out to determine the thermodynamic parameters suggested highly exothermic reactions with negative entropy values. The reusability and recycling studies involved stripping and radiolytic stability of the solvent systems which suggested reasonably encouraging results. While a DTPA solution in guanidine carbonate was found to back extract the extracted metal ion from the ionic liquid phase, the radiolytic stability of the CMPO-pillararenes were reasonably good.