Direct Quantitation of 135Cs in Spent Cs Adsorbent Used for the Decontamination of Radiocesium-Containing Water by Laser Ablation Inductively Coupled Plasma Mass Spectrometry.

The long-term safety assessment of spent Cs adsorbents produced during the decontamination of radiocesium-containing water at the Fukushima Daiichi nuclear power plant requires one to estimate their 135Cs content prior to final disposal. 135Cs is usually quantified by inductively coupled plasma mass spectrometry (ICP-MS), which necessitates the elution of Cs from Cs adsorbents. However, this approach suffers from the high radiation dose from 137Cs that is present in the contaminated water and Cs adsorption irreversibility. To address these challenges, we herein employed laser ablation ICP-MS for direct quantitation of 135Cs in Cs adsorbents and used a model Cs adsorbent prepared by immersion of a commercially available Cs adsorbent into radiocesium-containing liquid waste to verify the developed technique. Crushing and subsequent coating with a nitrocellulose-based curing agent provided a thin flat surface and thus allowed for stable solid sampling during laser ablation. The use of the 135Cs/137Cs ratio and 137Cs radioactivity obtained by gamma spectrometry achieved simple and precise quantitation of 135Cs. The obtained 135Cs/137Cs ratio of 0.41 ± 0.02 well agreed with that obtained for the original liquid waste sample by solution nebulization measurements, and the proposed method was concluded to be suitable for large-scale 135Cs quantitation, requiring only very small (<10 mg) samples with total 137Cs radioactivity.

Determination of 107Pd in Pd purified by selective precipitation from spent nuclear fuel by laser ablation ICP-MS.

Determination of radiopalladium 107Pd is required to ensure radiation safety of the Pd extracted from spent nuclear fuel for recycling or disposal. We employed nanosecond laser ablation inductively coupled plasma quadrupole mass spectrometry (ns-LA-ICP-QMS) to simplify the analytical procedure of 107Pd. Pd was separated through a selective Pd precipitation reaction induced by pulsed laser irradiation that reduces Pd(II) ions to metal Pd(0). Laser ablation facilitates direct measurement of the Pd precipitates, skipping the dissolution and dilution procedure with aqua regia and HCl, which causes serious corrosion damage to the introduction system of the ICP. In the present study, 102Pd in natural Pd standard solution was used as an internal standard owing to its absence in spent nuclear fuel. Pd precipitates with diameters ranging from 0.2 to 0.5 µm, obtained by pulsed laser irradiation, were embedded uniformly on the surface of the centrifugal filter to form a microscopically thin and flat Pd surface. The resulting homogeneous Pd layer is suitable for obtaining a stable signal ratio of 107Pd/102Pd (< 4%, 2RSD). The mass bias-corrected ratio of 107Pd/102Pd and the amount of 107Pd were 0.163 ± 0.004 and 17.8 ± 0.6 ng, respectively, which correspond to the values obtained by solution nebulization measurement after the dissolution of identical Pd precipitates. Graphical abstract ᅟ.

Determination of 107Pd in Pd Recovered by Laser-Induced Photoreduction with Inductively Coupled Plasma Mass Spectrometry.

Safety evaluation of a radioactive waste repository requires credible activity estimates confirmed by actual measurements. A long-lived radionuclide, 107Pd, which can be found in radioactive wastes, is one of the difficult-to-measure nuclides and results in a deficit in experimentally determined contents. In this study, a precipitation-based separation method has been developed for the determination of 107Pd with inductively coupled plasma mass spectrometry. The photoreduction induced by pulsed laser irradiation at 355 nm provides short-time and one-step recovery of Pd. The proposed method was verified by applying it to a spent nuclear fuel sample. To recover Pd efficiently, a natural Pd standard was employed as the Pd carrier. Taking advantage of the absence of 102Pd in spent nuclear fuel, 102Pd in the Pd carrier was utilized as the internal standard. The chemical yield of Pd was about 90% with virtually no impurities, allowing accurate quantification of 107Pd. The amount of 107Pd in the Pd precipitate was 17.3 ± 0.7 ng, equivalent to 239 ± 9 ng per mg of 238U in the sample.

Preparation of Microvolume Anion-Exchange Cartridge for Inductively Coupled Plasma Mass Spectrometry-Based Determination of (237)Np Content in Spent Nuclear Fuel.

Microvolume anion-exchange porous polymer disk-packed cartridges were prepared for Am/Np separation, which is required prior to the measurement of Neptunium-237 ((237)Np) with inductively coupled plasma mass spectrometry (ICPMS). Disks with a volume of 0.08 cm(3) were cut out from porous sheets having anion-exchange-group-containing polymer chains densely attached on the pore surface. Four different amine-based groups, N,N-dimethylaminoethyl methacrylate, trimethylammonium, diethylamine, and triethylenediamine (TEDA), were selected as the anion-exchange groups to be introduced into the porous sheets. The separation performances of Am/Np were evaluated using a standard solution of (243)Am, which had the same activity as its daughter nuclide (239)Np in secular equilibrium. (239)Np recovery of close to 100% with practically no contamination of (243)Am was achieved using the TEDA-introduced disk-packed cartridge. The time to elute (239)Np from the cartridge was approximately 40 s. The TEDA-introduced disk-packed cartridge was applied to the separation of Np from a spent nuclear fuel sample to confirm its separation performance. A known amount of (243)Am ((239)Np) was added to the spent nuclear fuel sample solution to monitor the chemical yield of Np. The chemical yield of Np calculated from a measured concentration of (239)Np was 90.4%. Am leakage in the Np-eluted solution was less than 1 ppt, corresponding to 0.001% of the original Am concentration in the sample. This indicates that no additional (239)Np was produced by the decay of the (243)Am remaining in the Np-eluted solution, thus providing a reliable chemical yield. U, which can cause a serious spectral interference involving the peak tail from the mass spectrum of (238)U, was thoroughly removed with the TEDA cartridge, providing interference-free measurement of (237)Np. The concentration of (237)Np obtained by ICPMS was 718 ± 12 ng/mg-U, which agrees well with the theoretically calculated value. 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-packed cartridge was reduced by 75%.

Low-carbohydrate diet by staple change attenuates postprandial GIP and CPR levels in type 2 diabetes patients.

AIMS: The aim of this study is to investigate the effects of a low-carbohydrate staple food (i.e., low-carbohydrate bread) on glucose and lipid metabolism and pancreatic and enteroendocrine hormone secretion in comparison with meals containing normal-carbohydrate bread, without consideration of the carbohydrate content of the side dishes. METHODS: T2DM patients (n = 41) were provided meals containing low-carbohydrate bread (LB) together with side dishes or normal-carbohydrate bread (NB) together with side dishes every other day as a breakfast. Blood glucose levels were evaluated by using a continuous glucose monitoring system; blood samples were collected before and 1 and 2 h after the breakfast. RESULTS: Postprandial blood glucose levels, plasma insulin, plasma glucose-dependent insulinotropic polypeptide (GIP) and plasma triglyceride were significantly lower and plasma glucagon levels were significantly higher in LB compared with those in NB. Plasma glucagon-like peptide-1 (GLP-1) levels did not differ in the LB and NB groups. CONCLUSIONS: These results indicate that changing only the carbohydrate content of the staple food has benefits on glucose and lipid metabolism in T2DM patients concomitant with the decrease of insulin and GIP secretion, which ameliorate body weight gain and insulin resistance.

Rapid separation of zirconium using microvolume anion-exchange cartridge for 93Zr determination with isotope dilution ICP-MS.

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 93Zr, a LLFP, was determined by ICP-MS after separating Zr from a spent nuclear fuel solution using a microvolume anion-exchange cartridge (TEDA cartridge). Zirconium in 9.4 M HCl was stably retained on the TEDA cartridge and readily eluted with 0.75 mL of a mixed solution of 9.4 M HCl and 0.01 M HF. The time taken to complete the Zr separation was 1.2 min. Almost all the other elements initially present in the spent nuclear fuel sample were removed, leading to accurate measurement of all six Zr isotopes (90Zr, 91Zr, 92Zr, 93Zr, 94Zr, and 96Zr). This demonstrated that the TEDA cartridge allowed highly selective separation of Zr regardless of its small bed volume of 0.08 cm3. The concentrations of these isotopes were determined by an isotope-dilution method using a natural Zr standard that has a different isotopic composition from that of the spent nuclear fuel sample. The amount of 93Zr in an initial spent nuclear fuel pellet was 1081 ±â€¯79 ng per mg of 238U. The measured concentrations of all Zr isotopes, as well as the isotopic composition, were consistent with values predicted using a burnup calculation code.

Preparation of an extractant-impregnated porous membrane for the high-speed separation of a metal ion.

A novel impregnation method of extractants into a porous polymeric support is described. Bis(2-ethylhexyl)phosphate (HDEHP) was impregnated onto an n-octadecylamino group of the polymer chain grafted onto the pore surface of a porous hollow-fiber membrane. First, an epoxy-group-containing polymer chain was appended onto the porous membrane by radiation-induced graft polymerization of glycidyl methacrylate (GMA). Second, n-octadecylamine was added to the graft chain via an epoxy-ring opening reaction to yield a hydrophobic group density of 3.0 mmol/g of the GMA-grafted fiber. Finally, HDEHP was impregnated to the n-octadecylamino group. The amount of impregnated HDEHP of 2.1 mmol/g of the GMA-grafted fiber was attained while retaining the liquid permeability of the porous membrane. An yttrium solution was forced to permeate through the pores of the HDEHP-impregnated porous hollow-fiber membrane. The higher permeation rate of the yttrium solution led to the higher adsorption rate of yttrium because of a negligible diffusional mass-transfer resistance. In addition, a high stability of impregnated HDEHP was observed after the repeated use of adsorption with 50 mg-Y/L yttrium solution and elution with 7 M nitric acid.

LA-ICP-MS of rare earth elements concentrated in cation-exchange resin particles for origin attribution of uranium ore concentrate.

Rare earth elements (REE) concentrated on cation-exchange resin particles were measured with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to obtain chondrite-normalized REE plots. The sensitivity of REE increased in ascending order of the atomic number, according to the sensitivity trend in pneumatic nebulization ICP-MS (PN-ICP-MS). The signal intensities of REE were nearly proportional to the concentrations of REE in the immersion solution used for particle-preparation. Minimum measurable concentration calculated from the net signals of REE was approximately 1 ng/g corresponding to 0.1 ng in the particle-preparation solution. In LA analysis, formation of oxide and hydroxide of the light REE and Ba which causes spectral interferences in the heavy REE measurement was effectively attenuated due to the solvent-free measurement capability, compared to conventional PN-ICP-MS. To evaluate the applicability of the proposed method, the REE-adsorbed particles prepared by immersing them in a U-bearing solution (commercially available U standard solution) were measured with LA-ICP-MS. Aside from the LA analysis, each concentration of REE in the same U standard solution was determined with conventional PN-ICP-MS after separating REE by cation-exchange chromatography. The concentrations of REE were ranging from 0.04 (Pr) to 1.08 (Dy) µg/g-U. The chondrite-normalized plot obtained through LA-ICP-MS analysis of the U standard sample exhibited close agreement with that obtained through the PN-ICP-MS of the REE-separated solution within the uncertainties.

Application of capillary electrophoresis with laser-induced fluorescence detection for the determination of trace neodymium in spent nuclear fuel using complexation with an emissive macrocyclic polyaminocarboxylate probe.

A simple and rapid method with low radiation exposure risk was developed for the determination of neodymium in spent nuclear fuel by capillary electrophoresis with laser-induced fluorescence detection using a fluorescent probe having a macrocyclic hexadentate polyaminocarboxylate structure. The concentration of Nd(III) in a spent nuclear fuel sample was determined with no interference from various matrix elements, including lanthanides and uranium (at a 200-fold excess), with 92 ± 3% recovery. This is due to high resolution based on establishing a ternary complex equilibrium during migration in which the hydroxyl ion plays an auxiliary role (log K(Ln-L-OH) = 3.9-5.3).

Highly sensitive detection of neodymium ion in small amount of spent nuclear fuel samples using novel fluorescent macrocyclic hexadentate polyaminocarboxylate probe in capillary electrophoresis-laser-induced fluorescence detection.

A rapid and high-sensitive detection method for the total concentration of Nd ion (total Nd) in a small amount of a spent nuclear fuel sample is urgently required since the precise quantification of total Nd ion makes it possible for burnup (degree of fuel consumption) to be determined. In this work, a capillary electrophoresis-laser-induced fluorescent detection method (CE-LIF) is proposed for the analysis of total Nd in a spent fuel sample solution, with the use of a newly synthesized metal fluorescent probe which has a fluorescein and a macrocylic hexadentate chelating group, FTC-ABNOTA, for lanthanide (Ln) ions. Ln ions were derivatized to form a strongly fluorescent complex with the probe to suppress the quenching of the ligand-centered emission. The detection of Ln complexes in the CE-LIF indicated that the interaction between Ln ions and the FTC-ABNOTA was strong enough not to dissociate during migration. The mutual separation among the Ln-FTC-ABNOTA complexes in CE-LIF was achieved by pH control providing a dynamic ternary complexation (DTC) with hydroxide ions. Using the DTC separation mode, a high resolution of Nd from other Ln ions with high resolution of 1.3-1.9 and a theoretical plate number of 68,000, and a very low detection limit of 22 pM (3.2 ppt, 0.11 attomole amount basis) were successfully obtained. A simulated spent fuel sample containing various metal ions was examined in this method with a good quantification result of 102.1% recovery obtained even with a large excess of U.

Modification of a porous sheet (MAPS) for the high-performance solid-phase extraction of trace and ultratrace elements by radiation-induced graft polymerization.

In this review, the preparation of a novel porous sheet designed for solid-phase extraction (SPE) and a comparison of the preconcentration performance of metal ions with conventional sorbents are described. A porous sheet (MAPS) with an average pore diameter, porosity, and a thickness of 1.0 microm, 75%, and 2 mm, respectively, 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 a 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 analyses of real samples.