The use of poly(acrylamide-acrylic acid)-montmorillonite composite for preparing low-activity 60Co, 65Zn, 134,137Cs mixed sealed source for radiometric calibration purposes

Poly(acrylamide-acrylic acid)-montmorillonite composite [P(AAm-MA)-M] was synthesized and used for preparing ⁶⁰Co, ⁶⁵Zn, ^134,137Cs mixed sealed source. The synthesis procedure was based on ??-induced polymerization of polyacrylamide (PAAm) in the presence of acrylic acid (AA), clay minerals (montmorillonite, M), and N,N??-methylenebisacrylamide (NMBA) as a cross-linker. The adsorbent functionality was assayed using FTIR spectroscopy and thermal analysis. The distribution coefficients of ⁶⁰Co(II), ⁶⁵Zn(II), and ^134,137Cs(I) ions on P(AAm-MA)-M were determined in relation to HCl concentration. P(AAm-MA)-M was loaded with ⁶⁰Co, ⁶⁵Zn, and ^134,137Cs by equilibrating it (0.5 g) with a mixed solution of ⁶⁰Co, ⁶⁵Zn, and ^134,137Cs at pH 3 (HCl) for 24 h at 25 ± 1°C. Mixed sealed source containing 5.3, 0.03, 0.05, and 1.05 ??Ci of ⁶⁰Co, ⁶⁵Zn, ¹³⁴Cs, and ¹³⁷Cs, respectively, was prepared by packing 100 mg of the loaded matrix in the cylindrical cavity of a Chinese Artelone capsule. The sealed source was subjected to quality control tests.     

Synthesis and characterization of zirconyl molybdopyrophosphate and its application for preparing 137Cs/137m Ba radioisotope generator

Semicrystalline zirconyl molybdopyrophosphate (ZMPP) ion exchanger was synthesized and characterized by thermal analysis, IR spectroscopy, and X-ray diffraction and was used for preparing ¹³⁷Cs/^137m Ba radioisotope generator. The interaction of ¹³⁴Cs radionuclides in HCl solutions was studied by batch equilibration method. The corresponding distribution coefficients were determined in relation to the acid concentration. Cesium-137 was loaded onto 1 g of zirconyl molybdopyrophosphate packed in 0.6 cm i.d. column. Elution of the generated ^137m Ba was examined in relation to the chemical composition and flow rate of the eluent. Barium-137m was obtained with high and reproducible elution yield and high chemical and radionuclidic purity.     

Potential use of an irradiated natural tin target for preparation of a mixed sealed source based on 12-tungstocerate gel matrix for radiometric calibration purposes

Irradiated natural tin target and 12-tungstocerate gel matrix were used for preparing a ¹¹³Sn and ^124,125Sb sealed source. The distribution coefficients of ¹¹³Sn/^113m In and ^124,125Sb ions on 12-tungstocerate gel matrix were determined in relation to HCl concentration. 12-Tungstocerate gel matrix was loaded with ¹¹³Sn/^113m In and ^124,125Sb by equilibrating an irradiated Sn(IV) solution with 0.5 g of the matrix at pH 1 (HCl) for 24 h at 25 ± 1°C. A mixed sealed source of ¹¹³Sn/^113m In and ^124,125Sb was prepared by packing 105 mg of the loaded matrix in the cylindrical cavity of a Chinese artelone capsule. The activity of the source was in the millicurie range. The source successfully passed quality control tests.     

Adsorption and Separation of <Superscript>152+154</Superscript>Eu(III) and <Superscript>60</Superscript>Co(II) Using Cerium(IV) Tungstate

Samples of cerium(IV) tungstate (CeW) inorganic ion exchanger were synthesized using different Ce(IV) salts: (NH₄)₂Ce(NO₃)₆·2H₂O, (NH₄)₄Ce(SO₄)₄·2H₂O, and Ce(SO₄)₂·4H₂O. The samples were characterized using FT-IR and X-ray diffraction. The adsorption behavior of ^152+154Eu(III) and ⁶⁰Co(II) on CeW was studied under batch and dynamic conditions. Factors influencing the adsorption kinetics were examined. Loading and elution behavior of both ions was studied using different eluents. Complete separation of Eu(III) and Co(II) (^152+154Eu and ⁶⁰Co tracers) was achieved using small columns packed with CeW.     

Preparation of high-purity 68Ga solutions by ion exchange in mixed acetone-hydrochloric acid medium

Ion-exchange behavior of ⁶⁸Ga in the mixed HCl-acetone medium on cation and anion exchangers was studied. The equilibrium gravimetric distribution coefficients of ⁶⁸Ga on Dowex AG 50W×8 strongly acidic cation exchanger in the H⁺ form and on Dowex AG 1×8 strongly basic anion exchanger in the Cl^? form in mixed HCl-acetone solutions at HCl concentrations in the range 0.1–3 M and acetone volume fractions in the range 0–90% were determined. The dynamic characteristics of the ⁶⁸Ga ion exchange in mixed HCl-acetone solutions were studied. A process based on the data obtained was developed for preparing ⁶⁸Ga solutions in 0.1 MHCl of high chemical and radiochemical purity, suitable for producing ⁶⁸Ga radiopharmaceuticals of required quality (radiochemical purity 98.1 ± 1.4%).     

Adsorption of some radionuclides from their aqueous solutions using zirconium molybdate ion exchanger

Zirconium molybdate ion exchanger prepared from equimolar amounts of sodium molybdate and zirconyl chloride was used as an effective sorbent for the absorption of some radionuclides from their aqueous solutions. The zirconium molybdate sorbent was characterized by IR spectra and X-ray diffraction. The adsorption behavior of zirconium molybdate toward Cs(I) (¹³⁴Cs), Co(II) (⁶⁰Co), Zn(II) (⁶⁵Zn), and Eu(III) (^{152, 154}Eu) ions in aqueous solutions was studied in relation to the contact time, composition of aqueous solutions, and temperature. The separation factors of the radionuclides in sorption on zirconium molybdate were determined. The efficiency of the recovery and separation of the radionuclides on zirconium molybdate was assessed. Published in Russian in Radiokhimiya, 2006, Vol. 48, No. 4, pp. 347–351. The text was submitted by the authors in English.     

Preparation of a novel zwitterionic graphene oxide-based adsorbent to remove of heavy metal ions from water: Modeling and comparative studies

A novel zwitterionic graphene oxide-based adsorbent was first synthesized in a multistep procedure including the successive grafting of bis(2-pyridylmethyl)amino groups (BPED) and 1,3-propanesultone (PS) onto graphene oxide (GO) sheets. Then, the as-prepared materials were used as adsorbent for the removal of metal ions from aqueous solutions. The influence of solution pH, contact time, metal ion concentration, and temperature onto the adsorption capacity of the zwitterionic GO-BPED-PS adsorbent was investigated and compared with the GO-BPED adsorbent. In particular, it was shown that the maximum adsorption capacities of the GO-BPED-PS adsorbent were as high as 4.174 ± 0.098 mmol.g^?1 for the Ni(II) ions and 3.902 ± 0.092 mmol.g^?1 for the Co(II) ions under optimal experimental conditions (metal ion concentration = 250 mg.L^?1, pH = 7 and T = 293 K). In addition, the adsorption behaviors of Ni(II) and Co(II) ions onto both the GO-BPED and GO-BPED-PS adsorbents fitted well with a pseudo-second-order kinetic model and a Jossens isotherm model. Moreover, adsorption thermodynamics of Ni(II) and Co(II) ions have been studied at various temperatures and confirmed the exothermic adsorption nature of the adsorption process onto the GO-BPED-PS adsorbent. Furthermore, the zwitterionic GO-BPED-PS adsorbent retained good adsorption properties after recycling 18 times which is much better than the conventional adsorbents.     

Simulations and modeling of radioactivity buildup due to corrosion products in ion exchanger and filters of a typical PWR

A set of coupled first-order differential equations have been developed to simulate the corrosion product activity in ion exchanger and filters of a typical pressurized water reactor (PWR). Computer program CPAIR-RC has been modified for the current study to include the effect of nonlinear acceleration of corrosion on corrosion product activities. Simulations for five corrosion products ⁵⁹Fe, ⁹⁹Mo, ⁵⁶Mn, ⁵⁸Co, and ⁶⁰Co have been carried out. Simulation results show that the activities due to ⁵⁹Fe, ⁹⁹Mo, and ⁵⁶Mn saturate within approximately 1000 h of reactor operation. However, the activities due to ⁵⁸Co and ⁶⁰Co keep on accumulating in the ion exchanger of PWR during this time. The activity buildup in the ion exchanger due to ⁵⁶Mn starts after 77 h of reactor operation. When flow rate perturbations are introduced by decreasing flow rate to 40% of rated value, the activity due to ⁵⁶Mn saturates at the value of 1.27 × 10⁻³ μCi cm⁻³. For the case of nonlinearly acceelerating corrosion with a pump coast down, the activity for ⁵⁹Fe shows an initial drop with a decrease in flow rates. The activity drops from 2.37 × 10⁻² to 2.33 × 10⁻² μCi cm⁻³ before the reactor scram. The corrosion product activities calculated by the CPAIR-RC program are compared with some of the experimental data available in literature and show fair agreement. Published in Russian in Radiokhimiya, 2009, Vol. 51, No. 1, pp. 40–46. The test was submitted by the authors in English.     

Chromatographic separation of 65Zn from radioactive tellurium waste solution using alumina column

High-purity ⁶⁵Zn was separated from a mixture containing ^{121,121m,123m,127}Te, ⁶⁵Zn, ⁵⁴Mn, ⁶⁰Co, ^110m Ag, ¹²⁵Sb, and ¹³⁴Cs using a small chromatographic alumina column. Samples of aged radioactive tellurium waste were dissolved in alkali solutions (1 and 5 M NaOH) and fed into preconditioned 1.0 g alumina columns at ～50°C. The columns were washed with 1 M NaOH or successively with 5 and 1 M NaOH. ⁶⁵Zn was quantitatively retained in the alumina column in the course of feeding and washing the column with 1 M NaOH. Solutions of NH₄Cl-NH₃, NH₄Cl-HCl, and HCl were studied as eluents for ⁶⁵Zn from the alumina column. 2 M HCl ensured the highest elution yield (88.7 ± 1.7%) with the ⁶⁵Zn radionuclidic purity of 99.4 ± 0.02%.     

Effects of γ Radiation on C60 Fullerene in CCI4 Solution

Abstract

By treating a CCI₄ solution of C₆₀ in a sealed ampoule under argon with γ radiation generated by a ⁶⁰Co source, chlorinated and trichloromethylated C₆₀ oligomers (dimers, trimers) are produced. A total radiation dose of 122 kGy was used.     

Synthesis and characterization of some chelating polymers bearing maleic acid and/or sodium maleate moieties for removal of some toxic heavy metal ions

Chelating copolymers (CCPs) bearing carboxylic acid and/or carboxylate moieties based on ethyl methacrylate in the absence and in the presence of divinyl benzene as a crosslinker were prepared via new emulsion copolymerization route. The obtained CCPs were characterized by (FT-IR, ¹HNMR, TEM, GPC, and TGA). Furthermore, the prepared CCPs have been tested as adsorbents for various toxic heavy metal ions. They showed higher sorption capacities toward transition metal ions such as (Co(II) and Ni(II)) and much less sorption capacity for (Cd(II) and Pb(II)). The optimum conditions for metal ion uptake such as time, pH, and comonomer concentrations of different weight percent (wt%) as well as the sorption kinetics were investigated. A high recovery about 90–93 % was obtained using HCl as an eluent agent.     

Fabrication of electrically conductive membrane electrode of gelatin-tin (IV) phosphate nanocomposite for the detection of cobalt (II) ions

Gelatin-tin (IV) phosphate nanocomposite (GT/TPNC) ion exchanger was synthesized by mixing gelatin gel into the precipitates of tin (IV) phosphate using sol–gel method. GT/TPNC was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ion exchange capacity of GT/TPNC was reported to be1.44?meq/g. The material was found monofunctional as indicated from pH titration curves. The distribution coefficient of different metal ions such as Zn²⁺ (42.10), Cd²⁺ (37.93), Mg²⁺ (33.33), Cu²⁺ (33.21), Al³⁺ (14.28), Pb²⁺ (6.06), Ni²⁺ (12.50) and Co²⁺ (50.0) was studied using GT/TPNC ion exchanger. The distribution studies confirmed the selectivity of GT/TPNC for Co (II). The photocatalytical degradation of MB was found to be 78% within 5 h of solar illumination using GT/TPNC. Some binary separations such as Co²⁺–Pb²⁺, Cd²⁺–Ni²⁺, Co²⁺–Mg²⁺, Mg²⁺–Zn²⁺, Pb²⁺–Zn²⁺, Cu²⁺–Al³⁺, Al³⁺–Cd²⁺, Ni²⁺–Cu²⁺ were attempted using GT/TPNC ion exchanger. GT/TPNC was explored for the fabrication of ion-sensitive membrane electrode for the determination of Co (II) in the water system. The membrane electrode was found mechanically more stable with quick response time (30?s) and a wide pH working range (4.0–7.0).     

Relative Bioavailability and Pharmacokinetic Parameters Following Adminstration of Single Oral Dose (2×150 mg) of Chloroquine Tablet in Healthy Subjects

Abstract

The bioavailability ot Chloroquine phosphate (150 mg base) film coated tablet (manufactured by Pars - Darou Co. Iran) was compared with that ot the Resochin tablet (Bayer, Germany) in seven healthy male and female volunteers. Blood samples were collected up to 14 days utter oral dosing of 300 nig and chloroquine serum concentrations were determined by means ot High Performance Liquid Chromatography (HPLC). From the analysis ot serum samples the following pharmacokinetic parameters were obtained: the absorption rate of test tablet and that of reference were 0.25 h^?1 and 0.34 h^?1 respectively; maximum serum concentration of both tablets was nearly equal, 81.6±25 and 83.4±27 ng/ml (for test and reference tablets respectively); time to reaching C_max (t_max) was also very similar, 4±1.6 for test and 4±1.0 h for reference; the area under the serum concentration-time curve [AUC(O -)] of 6976 ng.ml^?1.h±1967 for test and 6446 ng.ml^?1.h ± 2460 for reference tablets were found using trapezoidal rule. By evaluating of the r=(T/R)×100 for each parameters, the test tablet was found to be bioequivalent to Resochin at p = 0.05.     

Depth profile XPS analysis of polymeric materials by C<Subscript>60</Subscript><Superscript>+</Superscript> ion sputtering

When the depth profile of chemical composition is studied with X-ray photoelectron spectroscopy (XPS), the Ar⁺ ion sputtering method is generally adopted. However, in the case of polymers, chemical composition is destroyed, and so it is impossible to obtain accurate depth profile on polymers. In this research, the depth profile XPS analysis of aliphatic polymers, aromatic polymers, fluorine containing polymers, and natural polymers were conducted with the sputtering source being C₆₀ ⁺ ion, and the degree of damage was examined while comparing the results with the case of conventional Ar⁺ ion. It was found that Ar⁺ ion induces significant carbonization in all the polymers above-mentioned. Meanwhile, it turned out that C₆₀ ⁺ ion causes little damage to most polymers. However, in the case of the non-aromatic polymers containing halogen, hydroxyl, carboxyl, and ether groups in their backbones, the following three damage modes were found: (1) the functional group ratio changes by over ±10%; (2) new functional groups are formed; (3) the above (1) and (2) phenomena occur simultaneously.     

<Superscript>172</Superscript>Hf → <Superscript>172</Superscript>Lu Radionuclide Generator Based on a Reverse-Tandem Separation Scheme

The distribution coefficients of Hf(IV) and Lu(III) between Dowex 50W×8 cation exchanger or Dowex 1×8 anion exchanger and mixed HCl–H₂C₂O₄ solutions and between Dowex 50W×8 cation exchanger or Dowex 1×8 anion exchanger and citric acid solutions were determined. A number of modifications of the ¹⁷²Hf → ¹⁷²Lu generator, based on reverse separation schemes, were examined. Systems consisting of an anion-exchange resin and a solution of appropriate organic acid were taken as a chemical basis of the generator. Irreversible sorption of ¹⁷²Lu in generator columns was studied. The optimum operation mode of the ¹⁷²Hf → ¹⁷²Lu generator based on the reverse-tandem scheme with periodic transfer of the parent radionuclide into the liquid phase was determined.     

Preparation of radioiodinated bambuterol hydrochloride as beta receptors imaging agent

Bambuterol·HCl was successfully labeled with ¹²⁵I via direct electrophilic substitution at ambient temperature. The effect of reaction parameters such as Bambuterol amount, CAT amount, pH of the reaction mixture, reaction temperature, and reaction time and the in vitro stability of ¹²⁵I-Bambuterol·HCl were studied. The maximum yield of ¹²⁵I-Bambuterol·HCl was 92.5 ± 1.9%. The yield was determined by paper electrophoresis. In vitro stability study showed that it is preferred to use the freshly prepared agent. Biodistribution studies showed high uptake of ¹²⁵I-Bambuterol·HCl in liver and lungs (16 ± 0.15 and 4.3 ± 0.08% injected dose/g tissue, respectively, at 5 min post injection). The uptake in liver and lung remained high up to 1 h, as β₂-receptors are located mainly at the liver and lungs (bronchial smooth muscles). The clearance of ¹²⁵I-Bambuterol·HCl from mice appeared to be mainly via the renal pathway. Radioiodinated Bambuterol·HCl shows promise as novel selective β₂-adrenoceptor imaging agent.     

Onychopharmacokinetics of terbinafine hydrochloride penetration from a novel topical formulation into the human nail in vitro

This study determined the onychopharmacokinetics, nail absorption, distribution, and penetration of [¹⁴C]-terbinafine HCl in a new topical formulation into/through the human finger nail using the in vitro finite dose model. This study determined the penetration rate of terbinafine HCl from multiple doses of topical formulation applied daily for 14 days. Results showed that the total dose recovery (mass balance) was almost 100%. The concentration of terbinafine HCl in the deeper nail plate (ventral/intermediate layers) and the cotton-pad nail bed samples after the 14-day treatment were 613?±?145 and (±S.D.) and 27?±?1.2 µg/cm³ (or 1.9?±?0.6 µg/cm³ daily) on average, respectively. In comparison with nail concentration data from the literature for other topical terbinatine formulations, our results show that higher amounts of terbinafine HCl reached the deep nail plate and/or the nail bed after a 14-day topical treatment with this topical formulation in vitro.     

Radon exhalation rate measurement in the environment of Hassan district of southern India

The radon exhalation rate from soil and building materials collected from the Hassan district of southern India was studied by the sealed can technique. The surface exhalation rates of the building materials were found to vary from 13.07 ± 0.19 to 430 ± 9 mBq m^–2 h^–1 with a mean value of 141 ± 4 mBq m^–2 h^–1. The surface exhalation rates of the soil samples were found to vary from 36.5 ± 0.8 mBq m^–2 h^–1 to 376 ± 7 mBq m^–2 h^–1 with a mean value of 140 ± 4 mBq m^–2 h^–1. Good positive correlation was observed between the effective radium content and radon exhalation rate for both soil and building materials. Annual effective dose and α-index have also been estimated for the population of the region.     

A study of the ion-exchange behavior of Bi as a homolog of element 115 in dilute hydrohalic acid solutions

The ion-exchange behavior of Bi, a light homolog of element 115, in dilute HCl and HBr solutions was studied. The distribution coefficients of Bi, Pb, and other elements were determined in relation to the acid concentration and kind of the ion exchanger. From 0.25–0.5 M HCl and HBr, Bi is weakly sorbed by the cation exchanger with the distribution coefficients K _d ≤ 10, but is strongly sorbed (K _d ≥ 10⁴) by the anion exchanger, which proves formation of negatively charged complexes in such solutions. High separation factors (≥10⁵–10⁶) of Bi from actinide and other elements were obtained. The distribution coefficients of Bi and Pb differ considerably, which was used for their separation. The optimum conditions were found for repeated isolation of the short-lived isotopes ²¹¹Bi (2.1 min), ²¹²Bi (60.6 min), and ²¹³Bi (45.6 min) and for their separation from the long-lived parent radionuclides (Th, Ac, Ra, Pb) used as the initial elements in various generator systems. The possibility of isolation of element 115 and its decay products in the continuous on-line mode was demonstrated.     

Adsorption characteristics of noble metals on the strongly basic anion exchanger Purolite A-400TL

Ion exchange is an alternative process for uptake of noble metals from aqueous solutions. In the present study, the sorption of Pd(II), Pt(IV), and Au(III) ions from aqueous solution was investigated by using Purolite A-400TL (strongly basic anion exchanger, gel, type I) in a batch adsorption system as a function of time (1 min–4 h). Initial Pd(II) concentration (100–1000 mg/L), beads size (0.425–0.85 mm), rate of phases mixing (0–180 rpm), and temperatures (ambient, 313 K) were taken into account during the Pd(II) sorption process. Moreover, the column flow adsorption study was carried out, and the breakthrough curves were obtained for Pd(II) ions. The equilibrium, kinetic, desorption, and ion-exchange resin reuse studies were carried out. The experimental results showed that Purolite A-400TL—the strongly basic anion-exchange resin could be used effectively for the removal of noble metal ions from the aqueous medium. The kinetics of sorption process is fast and the resin could be reused without reduction of capacity (three cycles of sorption–desorption, the reduction of capacity is smaller than 1 %). The column studies indicated that in the dilute acidic solution (0.1 M HCl) the working anion exchange capacity is high (0.0685 mg/cm³) in comparison with the other SBA resins examined under the same experimental conditions, e.g., Amberlite IRA-458 (0.0510 mg/cm³), Amberlyst A-29 (0.0490 mg/cm³), Dowex MSA-1 (0.0616 mg/cm³), Dowex MSA-2 (0.0563 mg/cm³), Varion ADM (0.0480 mg/cm³), and Varion ATM (0.0490 mg/cm³) etc. The highest % of Pd(II) desorption was obtained using thiourea, acidic thiourea, sodium hydroxide, and ammonium hydroxide as eluting agents (%D1 was in the range of 23.9–46.9 mg/g).