Recovery of hafnium radioisotopes from a proton irradiated tantalum target

The^178m2Hf nucleus, with its long half-life (31 y) and high-spin isomeric state (16⁺) is desired for new and exotic nuclear physics studies. The Los Alamos Radioisotope Program irradiated a kilogram of natural tantalum at the Los Alamos Meson Physics Facility in early 1981. After fifteen years of decay, this target was ideal for the recovery of^178m2Hf. There was more than a millicurie of^178m2Hf produced during this irradiation and there has been a sufficient period of time for most of the other hafnium radioisotopes to decayed away. Traditionally, separation techniques for recovering hafnium isotopes from tantalum targets employ solvent extractions with reagents that are considered hazardous. These techniques are no longer condoned because they generate a mixed-waste (radioactive and hazardous components) that can not be treated for disposal. In this paper we describe a new and unique procedure for the recovery of hafnium radioisotopes from a highly radioactive, proton irradiated, tantalum target using reagents that do not contribute a hazardous waste component.     

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...     

Radiochemical separation of 88Y from a SrCl2 target using chelating resin Chelex 100

Summary Yttrium-88 was produced from irradiation of a SrCl₂ target (4.8 g, pressed into a 19 mm disc) by 33 MeV proton beam at a current of up to 90 mA. Chelating resin Chelex 100 (H⁺ form, 100-200 mesh) was used for the separation of yttrium radionuclides (including ⁸⁸Y) from strontium. 0.01M nitric acid was used for the dissolution of target (100 ml), retention of Y and elution of Sr (200 ml). For the elution of yttrium, 25 ml 1M HNO₃ was employed. The column was 4 cm long with internal diameter of 1.6 cm. The flow rate was 1 ml/min throughout the separation procedure. The ⁸⁸Y recovery yield was 94% average and the stable Sr content in the final product (5 ml 0.1M HCl) was estimated to be less than 3 ppm.     

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.     

Separation of no-carrier-added <Superscript>107,109</Superscript>Cd from proton induced silver target: classical chemistry still relevant

The classical chemistry like precipitation technique is relevant even in modern days trans-disciplinary research from the view point of green chemistry. A definite demand of no-carrier-added (nca) cadmium tracers, namely, ^107,109Cd, has been realized for diverse applications. Development of efficient separation technique is therefore important to address the purity of the tracers for various applications. No-carrier-added ^107,109Cd radionuclides were produced by bombarding natural silver target matrix with 13 MeV protons, which gave ~15 MBq/μA h yield for nca ¹⁰⁷Cd. The nca cadmium radionuclides were separated from the natural silver target matrix by precipitating Ag as AgCl. The developed method is an example wherein green chemistry is used in trans-disciplinary research. The method is also simple, fast, cost effective and environmentally benign.     

Preparation of carrier-free group tracers from a gold target irradiated by high-energy heavy ions

A rapid radiochemical separation procedure has been finished by using of radiochemical separation and -spectrum measurement methods. In this isolation procedure, tantalum nuclides produced by the irradiation of natural tungsten targets with 14 MeV neutrons were extracted by methyl isobutyl ketone (MIBK) in the system of HF-HNO₃ mixed solutions. It has been found that tantalum was rapidly and efficiently separated in the isolation procedure and the decontamination factors of tungsten were more than 10⁴. The procedure is simultaneously used to separate tantalum from tungsten bombarded with intermediate energy (47 MeV/u)¹⁸O beams. The measured -spectra showed that tantalum can be separated from most elements produced in the nuclear reactions except for a few elements.     

Preconcentration of trace nickel lons from aqueous solutions by using a new and low cost chelating polystyrene adsorbent

A simple and reliable method has been developed using chelating polymeric adsorbent (PSAHSB) to preconcentration of trace amount of Ni(II) ions from aqueous solutions under static loading conditions, and their determination by Ultraviolet and visible (UV–Vis) absorption spectroscopy. The influences of some analytical adsorption parameters, such as pH, temperature and contact time, the ionization constants of chelating groups in the adsorbent and desorption process were investigated. Maximum adsorption ≥98% was achieved at pH 3–7 after 20 min of contact time and the relative standard-deviation values were ≤5%. Adsorbed metal ions have been desorbed with 10 mL of 2 M HCl acid with the detection limit of 0.0157 μg m⁻¹. The Langmuir and Freundlich isotherm equations were used to describe adsorption behavior of the system at different temperatures. Kinetic and thermodynamic behavior of the adsorbent for Ni(II) ion preconcentration was also studied. The possible adsorption mechanism of Ni (II) ions onto modified adsorbent is also discussed. This method was applied efficiently to remove Ni (II) ions from environmental water samples.     

Nondigest liberation of biomarkers from plasma: a novel two-stage ultrafiltration approach

A simple procedure for sample preparation of human plasma by two stages of ultrafiltration using one device is described. Our approach is useful for nondigest liberation of biomarkers bound to albumin and other plasma proteins. The analyte contained in the ultrafiltrate can be directly analyzed without additional sample preparation, and quantified by 2-D RP-RP LC/MS.     

The production of 103Pd and 109Cd from a proton irradiated tandem natAg/natAg targets

This paper describes a new method for the production of ¹⁰³Pd and ¹⁰⁹Cd using the 66 MeV proton beam of iThemba LABS on a tandem natural silver target (Ag/Ag). The radiochemical separation of the Pd radionuclides (¹⁰³Pd, ¹⁰⁰Pd) from the bulk ^natAg was done using a Chelex-100 chelating resin column. The recovery of ¹⁰³Pd from the irradiated ^natAg target was found to be >98 % without any Ag or Rh impurities detected. The radiochemical separation of ¹⁰⁹Cd from the bulk ^natAg target was done by the precipitation of Ag ions by Cu followed by the separation of ¹⁰⁹Cd, traces of Ag, Cu²⁺ and Rh using a AG1-X10 anion exchange resin column. The recovery yield of ¹⁰⁹Cd was >99 % without any Ag or Rh impurities detected.     

Radiopharmaceutical Studies and Nuclear Medicine; Simultaneous <Superscript>68</Superscript>Ge and <Superscript>88</Superscript>Zr recovery from proton irradiated Ga/Nb capsules (LA-UR #03-2319)

Summary Germanium-68 (270.8 d, EC 100%) is the parent nuclide of ⁶⁸Ga, a β+ emitter important to positron emission tomography (PET). ⁶⁸Ge is obtained by a (p,x) induced nuclear reaction on natural Ga. A typical Ga target assembly consists of liquid Ga contained in a Nb capsule, since Nb is one of the few metals resistant to liquid Ga. Zirconium-88 (83.4 d, via ⁹³Nb(p, α2n)) is one longer-lived radioisotope generated by the proton irradiation of naturally mono-isotopic ⁹³Nb. It decays into ⁸⁸Y, which, in turn, has been considered a useful radiolabel surrogate for ⁹⁰Y in the investigation of radiolabeled compounds for cancer radioimmunotherapy. This paper introduces a wet chemical procedure for the processing of Nb/Ga target capsules and the simultaneous recovery of ⁶⁸Ge and ⁸⁸Zr.     

Bioremediation of uranium from waste effluents using novel biosorbents: a review

Journal of Radioanalytical and Nuclear Chemistry - Several treatments for the removal of toxic heavy metals like uranium from wastewater have been developed, but none of them are sufficiently...     

Separation and enrichment of six indicator polychlorinated biphenyls from real waters using a novel magnetic multiwalled carbon nanotube composite absorbent

A novel and effective magnetic multiwalled carbon nanotube composite for the separation and enrichment of polychlorinated biphenyls was developed. Fe₃O₄@SiO₂ core–shell structured nanoparticles were first synthesized, then the poly(sodium 4‐styrenesulfonate) was laid on its surface to prepare the polyanionic magnetic nanoparticles. The above materials were then grafted with polycationic multiwalled carbon nanotubes, which were modified by polydiallyl dimethyl ammonium chloride through the layer‐by‐layer self‐assembly approach. Its performance was tested by magnetic solid‐phase extraction and gas chromatography with mass spectrometry for the determination of six kinds of indicator polychlorinated biphenyls in water samples. Under optimal conditions, the spiked recoveries of several real samples for six kinds of polychlorinated biphenyls (PCB28, PCB52, PCB101, PCB138, PCB153, PCB180) were in the range of 73.4–99.5% with relative standard deviations varying from 1.5 to 8.4%. All target compounds showed good linearities in the tested range with correlation coefficients higher than 0.9993. The limits of quantification for six kinds of indicator polychlorinated biphenyls were between 0.018 and 0.039 ng/mL. The proposed method was successfully applied to analyze polychlorinated biphenyls in real water samples. Satisfactory results were obtained using the effective magnetic absorbent.     

Direct observation of a target cell of the leaf-closing factor by using novel fluorescence-labeled phyllanthurinolactone

We report the synthesis of the fluorescence-labeled probe 2 based on phyllanthurinolactone 1, which is a leaf-closing substance of Phyllanthus urinaria L. Bioorganic studies using probe 2 showed leaf-closing activity at 1 × 10⁻⁵ M, which was one-hundredth of that of the natural product 1. The fluorescence study using 2 revealed that the target cell for 1 is a motor cell and suggested that some receptors for 1 exist on the plasma membrane of the motor cell as with leaf-opening substances.     

Separation of 99Tc from low level radioactive liquid waste using hollow fiber supported liquid membrane: optimisation and performance evaluation

Journal of Radioanalytical and Nuclear Chemistry - Low level radioactive liquid waste (LLW) obtained after treatment of Intermediate level radioactive waste (ILW) is highly alkaline and rich in...     

Management of radioactive waste from molybdenum-99 production using low enriched uranium foil target and modified CINTICHEM process

Technetium-99m is the short-lived daughter product of the parent molybdenum-99, which is mainly produced by the fission of uranium-235. Management of radioactive waste is an integral part of fission ⁹⁹Mo production and has high priority during the planning, design, construction and operational phase of a molybdenum-99 production facility. Within the licensing procedure the strategy of waste management, including the route for the spent targets and long lived fission products has to be described and approved by the responsible authorities. Waste will be generated as solids, liquids, and gases, and will include material in the low, intermediate and even highly radioactive categories. Initial treatment of waste streams is usually required at the production site, prior to short or long term storage. This technology is established and generally available in countries with an existing nuclear industry, such as Pakistan. In some instances storage facilities may need to be constructed. On site, treatment of gaseous waste will be carried out in the production facility while off-site treatment will be performed for solids and liquid radioactive waste.