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Zr determination with isotope dilution ICP-MSAsai, Shiho; Hanzawa, Yukiko; Konda, Miki; Suzuki, Daisuke; Magara, Masaaki; Kimura, Takaumi; Ishihara, Ryo*; Saito, Kyoichi*; Yamada, Shinsuke*; Hirota, Hideyuki*
Talanta, 185, p.98 - 105, 2018/08
Times Cited Count：8 Percentile：31.98(Chemistry, Analytical)Estimating the risks associated with radiation from long-lived fission products (LLFP) in radioactive waste is essential to ensure the long-term safety of potential disposal sites. In this study, the amount of Zr, a LLFP, was determined by ICP-MS after separating Zr from a spent nuclear fuel solution using a microvolume anion-exchange cartridge (TEDA cartridge). The TEDA cartridge achieved highly selective separation of Zr regardless of its small bed volume of 0.08 cm
. The time taken to complete the Zr separation was 1.2 min with a flow rate of 1.5 mL/min, which was 10 times faster than that for a conventional anion-exchange resin column. Almost all the other elements were removed, leading to accurate measurement of Zr. The result connects experimental value to theoretical prediction provided by ORIGEN2, which requires verification. With the measured value, we demonstrated that the theoretical value is reliable enough to estimate radiation risks.
Saito, Kyoichi*; Asai, Shiho
Bunseki Kagaku, 66(11), p.771 - 782, 2017/11
Times Cited Count：1 Percentile：3.41(Chemistry, Analytical)Recovery and purification of rare metals, which are essential ingredients for highly functional materials, generally comes with operational difficulty. In this study, we have developed polymer adsorbents specially designed for highly-efficient adsorption of rare metal ions and exhibited their practical adsorption performances. Radiation-induced graft polymerization, one of the effective modification techniques for polymers, was employed for preparing the proposed adsorbents. Among such adsorbents, a 6-nylon fiber with nucleic-acid base, adenine, on the surface of the fiber demonstrated specific adsorption of ruthenium and palladium ions. In addition, a 6-nylon fiber with an extractant HDEHP (bis (2-ethylhexyl) phophoric acid) that has high affinity for lanthanides, achieved higher separation speed than a commercially available HDEHP-impregnated resin.
Asai, Shiho; Saito, Kyoichi*
Biomedical Research on Trace Elements, 28(1), p.1 - 10, 2017/04
Radionuclides are commonly determined with radiometry and mass spectrometry. For 
-emitting nuclides, the activities can be measured without chemical separation due to the strong penetration ability. In contrast, the measurements of alpha and beta-emitting nuclides are generally associated with tedious and time-consuming chemical separation procedures to remove concomitants. Thus, an adsorbent that achieves rapid separation is desirable to reduce separation time and workload. Our research team has developed compact cartridge-type solid phase extraction materials which enable to facilitate separation procedures. In this review, basic separation performances of the developed cartridges were overviewed along with two application examples to radionuclide-containing samples.
Saito, Kyoichi*; Kojima, Takashi*; Asai, Shiho
Bunseki Kagaku, 66(4), p.233 - 242, 2017/04
Times Cited Count：1 Percentile：3.41(Chemistry, Analytical)Insoluble cobalt ferrocyanide and sodium titanate specifically capture cesium and strontium ions, respectively, in water contaminated with radionuclides which is found in Fukushima Daiichi NPP. The inorganic compounds used in this study were formed as precipitates in the polymer chain grafted onto a commercially available 6-nylon fiber using radiation-induced graft polymerization. An impregnation structure with the precipitates entangled by the grafted polymer chain through an electrostatic interaction via multipoints was indicated. The resultant insoluble cobalt ferrocyanide- or sodium titanate-impregnated fiber exhibited a higher adsorption rate and adsorption capacity per gram of the inorganic compound for cesium or strontium ions in seawater than conventional granular adsorbents.
Sr measurementHorita, Takuma; Asai, Shiho; Konda, Miki; Hanzawa, Yukiko; Saito, Kyoichi*; Fujiwara, Kunio*; Sugo, Takanobu*; Kitatsuji, Yoshihiro
Bunseki Kagaku, 66(3), p.189 - 193, 2017/03
Times Cited Count：1 Percentile：3.41(Chemistry, Analytical)A Sr-selective adsorption fiber was prepared for rapid analysis of Sr content by using radiation-induced emulsion graft polymerization and subsequent chemical modification. A polyethylene fiber with a diameter of 13 
m was first immersed in a methanol solution of an epoxy-group-containing vinyl monomer, glycidyl methacrylate (GMA), and polyoxyethylene sorbitol ester (Tween20) as a surfactant for graft-polymerization of GMA. Octadecylamine was then bound to a polymer chain extending from the fiber surface providing hydrophobicity to the polymer chain. Dicyclohexano-18-crown-6 (DCH18C6) was finally impregnated onto the polymer chain via a hydrophobic interaction between the octadecyl moiety of the polymer chain and the cyclohexyl moiety of DCH18C6. The fiber surface structure, characterized by DCH18C6 molecules loosely entangled with polymer chains, afforded realizes the rapid and selective adsorption of Sr ions with an adsorption rate approximately 100 times higher than that of a commercially available Sr-selective resin (Sr Resin).
Np content in spent nuclear fuelAsai, Shiho; Hanzawa, Yukiko; Konda, Miki; Suzuki, Daisuke; Magara, Masaaki; Kimura, Takaumi; Ishihara, Ryo*; Saito, Kyoichi*; Yamada, Shinsuke*; Hirota, Hideyuki*
Analytical Chemistry, 88(6), p.3149 - 3155, 2016/03
Times Cited Count：8 Percentile：29.82(Chemistry, Analytical)Neptunium-237 (Np) is one of the major long-lived radionuclides found in spent nuclear fuel. To evaluate the long-term safety of a HLW repository, the Np content in spent nuclear fuel must be determined. In this study, micro-volume anion-exchange porous polymer disk-packed cartridges were prepared for Am-Np separation, which is required prior to the measurement of Np with ICP-MS. Disks with a volume of 0.08 cm were cut out from porous sheets having triethylenediamine (TEDA)-containing polymer chains densely attached on the pore surface. The resulting TEDA-introduced disk cartridge was applied to a spent nuclear fuel sample. The chemical yield of Np was 90.4%, which is sufficiently high for ICP-MS measurement of Np. Compared with the conventional separation technique using commercially available anion-exchange resin columns, the time required to adsorb, wash and elute Np using the TEDA-introduced disk cartridge was reduced by 75%.
Someya, Takaaki*; Asai, Shiho; Fujiwara, Kunio*; Sugo, Takanobu*; Umeno, Daisuke*; Saito, Kyoichi*
Nihon Kaisui Gakkai-Shi, 69(1), p.42 - 48, 2015/02
A large amount of seriously contaminated sea water with radioactive Cs has been reserved in semi-enclosed coastal sea area which is separated by silt fences and embankments. Insoluble cobalt ferrocyanide (Co-FC) microparticles-impregnated fiber was developed for removing Cs from the contaminated sea water. The resultant Co-FC-impregnated fiber was immersed in either nonradioactive or radioactive Cs solution. The adsorption isotherm well correlated with a Langmuir-type equation. In addition, mass-transfer capacity coefficients were determined by fitting the experimental data of the rate of Cs adsorption onto the Co-FC-impregnated fiber to theoretical adsorption curves based on the Cs concentration difference between the bulk and the interface in seawater as a driving force of the overall adsorption rate. Decontamination factors as functions of fiber weight and the contact time required for the removal of cesium ions from the contaminated seawater in a closed area were estimated.
Tanaka, Ryota*; Ishihara, Ryo*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*; Asai, Shiho; Yamada, Shinsuke*; Hirota, Hideyuki*
Separation Science and Technology, 49(1), p.154 - 159, 2014/01
Times Cited Count：4 Percentile：16.82(Chemistry, Multidisciplinary)Uchiyama, Shoichiro*; Ishihara, Ryo*; Umeno, Daisuke*; Saito, Kyoichi*; Yamada, Shinsuke*; Hirota, Hideyuki*; Asai, Shiho
Journal of Chemical Engineering of Japan, 46(6), p.414 - 419, 2013/06
Times Cited Count：7 Percentile：26.06(Engineering, Chemical)Wada, Go*; Ishihara, Ryo*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*; Asai, Shiho; Yamada, Shinsuke*; Hirota, Hideyuki*
Solvent Extraction and Ion Exchange, 31(2), p.210 - 220, 2013/02
Times Cited Count：2 Percentile：12.24(Chemistry, Multidisciplinary)A crosslinked chelating porous sheet was prepared by cografting ethylene glycol dimethacrylate (EGDMA) with glycidyl methacrylate onto an electron-beam-irradiated porous polyethylene sheet, followed by the introduction of an iminodiacetate group. At a molar percentage of EGDMA of 1.0 mol%, the sheet exhibited a maximum dynamic binding capacity for copper ions of 0.93 mmol/g, while the equilibrium binding capacity remained the same (1.2 mmol/g) as that of a non-crosslinked chelating porous sheet. The crosslinking of the grafted chain causes copper ions to lower their diffusion rate along the sheet thickness driven by the gradient of the amount of copper ions adsorbed.
Ishihara, Ryo*; Asai, Shiho; Otosaka, Shigeyoshi; Yamada, Shinsuke*; Hirota, Hideyuki*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*
Solvent Extraction and Ion Exchange, 30(2), p.171 - 180, 2012/02
Times Cited Count：8 Percentile：31.67(Chemistry, Multidisciplinary)Ishihara, Ryo*; Fujiwara, Kunio*; Harayama, Takato*; Okamura, Yusuke*; Uchiyama, Shoichiro*; Sugiyama, Mai*; Someya, Takaaki*; Amakai, Wataru*; Umino, Satoshi*; Ono, Tsubasa*; et al.
Journal of Nuclear Science and Technology, 48(10), p.1281 - 1284, 2011/10
Times Cited Count：44 Percentile：94.73(Nuclear Science & Technology)Wada, Go*; Ishihara, Ryo*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*; Asai, Shiho; Yamada, Shinsuke*; Hirota, Hideyuki*
Nihon Ion Kokan Gakkai-Shi, 22(2), p.47 - 52, 2011/01
no abstracts in English
Miyazawa, Tadashi*; Asari, Yuki*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*; Nagatani, Takeshi*; Yoshikawa, Naohito*; Motokawa, Ryuhei; Koizumi, Satoshi*
Nihon Kaisui Gakkai-Shi, 64(6), p.360 - 365, 2010/12
-octylphosphine oxide, and its adsorption/elution of bismuth ionsTanaka, Ryota*; Ishihara, Ryo*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*; Asai, Shiho; Yamada, Shinsuke*; Hirota, Hideyuki*
Reactive and Functional Polymers, 70(12), p.986 - 990, 2010/12
Times Cited Count：7 Percentile：29.11(Chemistry, Applied)Asai, Shiho; Kimura, Takaumi; Miyoshi, Kazuyoshi*; Saito, Kyoichi*; Yamada, Shinsuke*; Hirota, Hideyuki*
Nihon Ion Kokan Gakkai-Shi, 21(3), p.334 - 339, 2010/07
Asai, Shiho; Miyoshi, Kazuyoshi*; Saito, Kyoichi*
Analytical Sciences, 26(6), p.649 - 658, 2010/06
Times Cited Count：11 Percentile：9.82(Chemistry, Analytical)A preparation of novel porous sheet designed for solid-phase extraction (SPE) and a comparison of the preconcentration performance of metal ions with conventional sorbents are described in this review. A porous sheet (MAPS) was modified into an sorbent used for solid-phase extraction, by radiation-induced graft polymerization. Ion-exchange and chelating groups were immobilized onto polymer chains grafted to the MAPS. Also, extractants were impregnated via hydrophobic interaction with long alkyl chains introduced into the grafted polymer chains of the MAPS. The applicability of the resultant modified MAPSs was demonstrated by adopting them to the analyses of real samples.
Sawaki, Kenta*; Asai, Shiho; Watanabe, Kazuo; Sugo, Takanobu*; Saito, Kyoichi*
Maku, 33(1), p.32 - 38, 2008/01
TOPO, tri-n-octylphosphine oxide, as a neutral extractant was impregnated to the hydrophobic group of the polymer chain grafted onto a porous hollow-fiber membrane for an efficient metal-ion collection. A diol group,i.e., adjacent hydroxyl group was introduced into poly-glycidyl methacrylate(GMA) chain grafted onto the porous hollow-fiber membrane via the epoxy-ring-opening reaction with water, followed by a reaction of the remaining epoxy group with octadecanethiol (C
H
SH) to form an octadecanethiol group. The diol group reduced the amount of TOPO coagulatedon the graft chain, whereas the interaction of the octadecanethiol group of the graft chain with the hydrophobic part of TOPO enabled the impregnation of TOPO to the graft chain. A 1 mmol-Bi/L bismuth chloride solution was forced to permeate through the pores of the TOPO-impregnated porous hollow-fiber membrane with a density of TOPO impregnated of 1.3 mol/kg of the GMA-grafted porous hollow-fiber membrane and the pure water flux of 0.7 m/h at 0.1 MPa and 298 K. The equilibrium binding capacity of the membrane for bismuth ions was 0.22 mol/kg of the TOPO-impregnated porous hollow-fiber membrane, which was equivalent to a binding ratio of bismuth ion to impregnated TOPO of 1.0.
Asai, Shiho; Magara, Masaaki; Sakurai, Satoshi; Shinohara, Nobuo; Saito, Kyoichi*; Sugo, Takanobu*
Nihon Ion Kokan Gakkai-Shi, 18(4), p.486 - 491, 2007/10
Ishihara, Ryo*; Umeno, Daisuke*; Saito, Kyoichi*; Asai, Shiho; Sakurai, Satoshi; Shinohara, Nobuo; Sugo, Takanobu*
Nihon Ion Kokan Gakkai-Shi, 18(4), p.480 - 485, 2007/10
