Ionic liquid-salt based aqueous biphasic system for separation of 109Cd from silver target

Aqueous biphasic system (ABS) is greener alternative to the conventional liquid liquid extraction as ABS does not involve any organic or volatile reagents. Generally ABS systems are composed of polymer and salt rich phases. In this paper a new ABS system is proposed replacing polymer rich phase by water soluble room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium Chloride ([bmim]Cl) and kosmotropic salt K₂HPO₄. The system has been applied to separate the no-carrier-added (NCA) ¹⁰⁹Cd (T _1/2 = 462.6 days) from the α-particle irradiated bulk Ag target. The optimum separation condition was achieved with the addition of 6 M HNO₃ to the ABS, where ~87 % of the bulk Ag was extracted in the IL phase, leaving ~96 % NCA ¹⁰⁹Cd in the salt rich phase. The salt rich phase was re-extracted twice with the RTIL to free from bulk Ag. This process achieved an overall separation of 91 % NCA ¹⁰⁹Cd free from bulk Ag. The developed method demonstrates minimum requirement of RTIL to carry out the separation. The method is environmentally benign and cost effective.     

Production and separation of no-carrier-added 48V from 16O irradiated chlorine target

The viability of ground coal bottom ash as a potential Portland cement constituent to be used in building materials is assessed. Currently, coal fly ash is used to produce Portland cements and concretes. However, coal bottom ash is mainly landfilled. Gamma spectrometry analysis, compressive strength, physical and chemical testing were performed. The ground coal bottom ash activity concentration index (I = 1.03) was compared to that of the coal fly ash (I = 1.11) provided from the same thermo-electrical power plant. Ground coal bottom ash could be used in building materials in the same way as coal fly ash as a Portland cement constituent.

     

Wet-chemistry method for the separation of no-carrier-added 211At/211gPo from 209Bi target irradiated by alpha-beam in cyclotron

We present a fast and effective wet-chemistry method, used to obtain the pure alpha-emitter ²¹¹At/^211gPo (T _1/2 = 7.214 h/516 ms), produced by ²⁰⁹Bi(α,2n) reaction in NCA form. It is a selective radiochemical separation of the At radionuclides from the target and the impurities, characterized by a radionuclidic purity close to 100%, based on the dissolution and the dilution of the irradiated target in acidic medium, on the extraction with DIPE, followed by the back-extraction with NaOH. As a result, we obtain a yield greater than 90–97% in a range from 0.75M to 2.00M.     

Wet harvesting of no-carrier-added 211At from an irradiated 209Bi target for radiopharmaceutical applications

Astatine-211 is one of the most promising -emitters for targeted cancer radiotherapy. However, research and clinical trials involving ²¹¹At-labeled radiopharmaceuticals have often been impeded due to the irregular and sometimes inconveniently low recovery yields obtained by the currently used dry distillation procedure. Therefore, a wet harvesting procedure isolating ²¹¹At from an irradiated ²⁰⁹Bi target was explored. The procedure involves target dissolution in concentrated HNO₃ and extraction of the high oxidation state ²¹¹At activity with butyl or isopropyl ether. This method resulted in consistent and nearly quantitative yields. The activity was re-extracted in aqueous phase and applied to NIS6 UVW human glioma cells transfected with cDNA encoding the human sodium/iodide symporter (NIS). The significant and specific uptake of ²¹¹At activity by these cells suggests that in the ether phase, high oxidation state ²¹¹At is reduced to [²¹¹At]astatide anion. The synthesis of the first astatinated organic compound derived from wet harvested ²¹¹At, 3-astatobenzoic acid (ABA), was achieved.This work was supported by Grants EB002980, CA42324 and CA91927 from the U.S. National Institutes of Health. Special thanks go to Michael Dailey and Shawn Murphy from the Duke University Medical Center PET Cyclotron Department for providing us with ²¹¹At activities and to Kevin Alston for the preparation of the bismuth targets. NIS cDNA was kindly gifted by Dr. Sissy M. Jhiang from Ohio State University, Columbus, Ohio.     

Wet harvesting of no-carrier-added 211At from an irradiated 209Bi target for radiopharmaceutical applications

Astatine-211 is one of the most promising -emitters for targeted cancer radiotherapy. However, research and clinical trials involving ²¹¹At-labeled radiopharmaceuticals have often been impeded due to the irregular and sometimes inconveniently low recovery yields obtained by the currently used dry distillation procedure. Therefore, a wet harvesting procedure isolating ²¹¹At from an irradiated ²⁰⁹Bi target was explored. The procedure involves target dissolution in concentrated HNO₃ and extraction of the high oxidation state ²¹¹At activity with butyl or isopropyl ether. This method resulted in consistent and nearly quantitative yields. The activity was re-extracted in aqueous phase and applied to NIS6 UVW human glioma cells transfected with cDNA encoding the human sodium/iodide symporter (NIS). The significant and specific uptake of ²¹¹At activity by these cells suggests that in the ether phase, high oxidation state ²¹¹At is reduced to [²¹¹At]astatide anion. The synthesis of the first astatinated organic compound derived from wet harvested ²¹¹At, 3-astatobenzoic acid (ABA), was achieved.This work was supported by Grants EB002980, CA42324 and CA91927 from the U.S. National Institutes of Health. Special thanks go to Michael Dailey and Shawn Murphy from the Duke University Medical Center PET Cyclotron Department for providing us with ²¹¹At activities and to Kevin Alston for the preparation of the bismuth targets. NIS cDNA was kindly gifted by Dr. Sissy M. Jhiang from Ohio State University, Columbus, Ohio.     

Separation of 97Ru from niobium target using PEG based aqueous biphasic systems

Separation of no-carrier-added (NCA) ⁹⁷Ru from bulk niobium target has been carried out for the first time using green analytical technique, aqueous biphasic system. 50 % (w/v) polyethylene glycol (PEG)-4000, against 2 M solutions of various salts such as Na-citrate, Na-tartarate, Na-malonate, Na₂CO₃, NaHSO₃, Na₂SO₄, Na₂S₂O₃ K₂HPO₄, K₃PO₄, K₂CO₃ and 4 M KOH were employed at room temperature for the extraction of NCA ⁹⁷Ru from bulk niobium. Influence of molecular weight of PEG rich phase as well as pH of some salt rich phase (e.g., Na-tartarate) on the extraction behaviour of NCA ⁹⁷Ru into PEG rich phase was also observed. In the presence of sodium-tartarate salt solution, when volume of PEG-4000: Na-tartarate was 3:1, 91 % of NCA ⁹⁷Ru was extracted into the PEG rich phase without any contamination of niobium target. Dialysis of PEG rich phase containing NCA ⁹⁷Ru was carried out against deionised water to obtained pure NCA ⁹⁷Ru.     

Ionic liquid-salt aqueous two-phase extraction based on salting-out coupled with high-performance liquid chromatography for the determination of sulfonamides in water and food

Ionic liquid-salt aqueous two-phase extraction coupled with high-performance liquid chromatography with ultraviolet detection was developed for the determination of sulfonamides in water and food samples. In the procedure, the analytes were extracted from the aqueous samples into the ionic liquid top phase in one step. Three sulfonamides, sulfamerazine, sulfamethoxazole, and sulfamethizole were selected here as model compounds for developing and evaluating the method. The effects of various experimental parameters in extraction step were studied using two optimization methods, one variable at a time and Box–Behnken design. The results showed that the amount of sulfonamides did not have effect on the extraction efficiency. Therefore, a three-level Box–Behnken experimental design with three factors, which combined the response surface modeling, was used to optimize sulfonamides extraction. Under the most favorable extraction parameters, the detection limits (S/N?=?3) and quantification limits (S/N?=?10) of the proposed method for the target compounds were achieved within the range of 0.15–0.3 ng/mL and 0.5–1.0 ng/mL from spiked samples, respectively, which are lower than or comparable with other reported approaches applied to the determination of the same compounds. Finally, the proposed method was successfully applied to the determination of sulfonamide compounds in different water and food samples and satisfactory recoveries of spiked target compounds in real samples were obtained.     

Separation of bulk Pb and Bi from proton irradiated lead bismuth eutectic (LBE) target by DGA-N and TK-200 resins

Journal of Radioanalytical and Nuclear Chemistry - Poly (vinyl alcohol)-ethylene glycol (PVA-EG) composites were geared up using casting method. The PVA-EG composite films have been irradiated at...     

Enantioselective hydrogenation of polar substrates in inverted supercritical CO2/aqueous biphasic media

An inverted supercritical CO2/aqueous biphasic catalytic system allows highly enantioselective hydrogenation of polar water-soluble substrates and efficient recycling of the CO2-philic catalysts.     

A rapid method for the separation of 210 Po from 210 Pb by TIOA extraction

A rapid method for the separation of ²¹⁰ Po from ²¹⁰ Pb was developed utilizing extraction of triisooctylamine (TIOA)/xylenein HCl+H₂O₂ medium. Polonium in the form of PoCl ₆ ²– was extracted into TIOA phase and ²¹⁰Pb remains in the aqueous phase. Lead-²¹⁰ was determined by -countingof its granddaughter, ²¹⁰ Po ingrown from ²¹⁰ Pb forsome period of time. Distribution of ²¹⁰ Po and ²¹⁰Pb in TIOA and aqueous phases was investigated in various concentrations ofHCl media. Hydrogen peroxide was used to further decompose organic matterand to remove sulfur to prevent its deposition on the silver disc. The improvedprocedure resulted in a good chemical yield (80–95%) and a good á-resolution.     

A one-pot process based on P44414Cl-HCl aqueous biphasic system for recovering rare earth elements from NdFeB permanent magnet

Recovering critical metals from secondary resources have attracted great interest recently.In this work,a green one-pot leaching-extraction process based on tributyl（tetradecyl）phosphonium chloride (P₄₄₄₁₄Cl)aqueous biphasic system （ABS） was developed to efficiently recover rare earth elements （REEs） from Nd Fe B permanent magnet.The reaction process,phase separation mechanism,and operation conditions were thoroughly investigated.It is found that the P₄₄₄₁₄Cl-HCl ABS showed...     

Infrared and mass spectral studies of proton irradiated H2O + CO2 ice: Evidence for carbonic acid

The effects of proton irradiation on mixed H₂O + CO₂ (1:1) ices at 20 K were investigated by infrared and mass spectroscopy. Infrared bands due to several radical (HCO, CO₃) and molecular (CO) product species were identified. In addition, several new broad and complex i.r. features were observed. On slow warming, the broad features evolved into a 215–250 K residual film whose absorptions have been tentatively assigned to carbonic acid. This identification agrees with the spectral data for irradiated H₂O + ¹³CO₂ ice and the results of an approximate normal coordinate analysis.     

Oxidative halogenation of aromatic compounds in the Pb3O4-Hal−-CF3CO2H system

Conclusions Chlorination, bromination, and iodination of aromatic compounds may be carried out in the Pb₃O₄-Hal^–-CF₃CO₂H system at room temperature. Halogenation under these conditions is not complicated by side reactions which are usual when lead tetraacetate is taken as the oxidizing agent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2609–2611, November, 1987.     

Efficient separation of tocopherol homologues in vegetable oil by ionic‐liquid‐based countercurrent chromatography using a non‐aqueous biphasic system

Tocopherol homologues are important fat‐soluble bioactive compounds with high nutritional value. However, it is of great challenge to separate these homologues because of their high structural similarities. In this work, ionic‐liquid‐based countercurrent chromatography was used for the separation and purification of tocopherol homologues. Conventional countercurrent chromatography and ionic‐liquid‐based countercurrent chromatography solvent systems were evaluated in respect of partition coefficient, separation factor, and stationary phase retention factor to separate these targets. Kind of ionic liquids, amount of ionic liquid, and sample amount were systematically optimized. A novel countercurrent chromatography non‐aqueous biphasic system composed of n‐hexane‐methanol‐1‐butyl‐3‐methylimidazolium chloride was established. The baseline separation of tocopherol mixtures was obtained in one cycle process. The ionic liquid played a key role in the countercurrent chromatography separation, which resulted in difference of partition behavior of individual tocopherol in the whole system through different hydrogen‐bonding affinity. Finally, n‐hexane‐methanol‐1‐butyl‐3‐methylimidazolium chloride (5:5:3, v/v) water‐free biphasic system was successfully applied to separate tocopherol homologues from vegetable oil that was not achieved beforehand. This method can be widely employed to separate many similar molecules such as tocotrienols, tocomonoenols, and marine‐derived tocopherol in food samples.     

A superacid-catalyzed synthesis of porous membranes based on triazine frameworks for CO2 separation

A general strategy for the synthesis of porous, fluorescent, triazine-framework-based membranes with intrinsic porosity through an aromatic nitrile trimerization reaction is presented. The essence of this strategy lies in the use of a superacid to catalyze the cross-linking reaction efficiently at a low temperature, allowing porous polymer membrane architectures to be facilely derived. With functionalized triazine units, the membrane exhibits an increased selectivity for membrane separation of CO(2) over N(2). The good ideal CO(2)/N(2) selectivity of 29 ± 2 was achieved with a CO(2) permeability of 518 ± 25 barrer. Through this general synthesis protocol, a new class of porous polymer membranes with tunable functionalities and porosities can be derived, significantly expanding the currently limited library of polymers with intrinsic microporosity for synthesizing functional membranes in separation, catalysis, and energy storage/conversion.