• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.503-506
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• 2001

Separation of lithium isotopes was investigated by chemical ion exchange with a hydrous manganese(IV) oxide ion exchanger using an elution chromatography. The capacity of manganese(IV) oxide ion exchanger was 0.5 meq/g. One molar CH3COO Na solution was used as an eluent. The heavier isotope of lithium was enriched in the solution phase, while the lighter isotope was enriched in the ion exchanger phase. The separation factor was calculated according to the method of Glueckauf from the elution curve and isotopic assays. The single stage separation factor of lithium isotope pair fractionation was 1.021.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.451-456
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• 2007

Tetraazamacrocyclic ion exchangers tethered to Merrifield peptide resin (DTDM, TTTM) were prepared and the ion exchange capacity of these was characterized. The isotope separation of lithium was determined using breakthrough method of column chromatography. The isotope separation coefficient was strongly dependent on the ligand structure by Glueckauf's theory. We found that the isotope separation coefficients were increased as the values of distribution coefficients were increased. In this experiment the lighter isotope, 6Li was enriched in the resin phase, while the heavier isotope, 7Li in the solution phase. The ion radius of lighter isotope, 6Li was shorter than the heavier isotope, 7Li. The hydration number of lithium ion with the same charge became small as mass number was decreased. Because 6Li was more strongly retained in the resin than 7Li, the isotopes of lithium were separated with subsequent enrichment in the resin phase.

• Korean Journal of Materials Research
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• v.31 no.8
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• pp.465-470
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• 2021

Deuterium is a crucial clean energy source required for nuclear fusion and is a future resource needed in various industries and scientific fields. However, it is not easy to enrich deuterium because the proportion of deuterium in the hydrogen mixture is scarce, at approximately 0.016 %. Furthermore, the physical and chemical properties of the hydrogen mixture and deuterium are very similar. Therefore, the efficient separation of deuterium from hydrogen mixtures is often a significant challenge when using modern separation technologies. Recently, to effectively separate deuterium, studies utilizing the 'Kinetic Quantum Sieving Effect (KQS)' of porous materials are increasing. Therefore, in this review, two different strategies have been discussed for improving KQS efficiency for hydrogen isotope separation performance using nanoporous materials. One is the gating effect, which precisely controls the aperture locally by adjusting the temperature and pressure. The second is the breathing phenomenon, utilizing the volume change of the structure from closed system to open system. It has been reported that efficient hydrogen isotope separation is possible using these two methods, and each of these effects is described in detail in this review. In addition, a specific-isotope responsive system (e.g., 2nd breathing effect in MIL-53) has recently been discovered and is described here as well.

• Membrane Journal
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• v.13 no.3
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• pp.154-161
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• 2003

We measured the permeation characteristics of water with the hydrophobic PTFE membranes dependent on water temperature to confirm the separation of oxygen isotopes using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD). Isotopic concentrations of $H_2^{16}O$ and $H_2^{18}O$ of the permeated water vapor were measured by Diode Laser Absorption Spectroscopy. Concentrations of the heavy oxygen isotopes in the permeated water vapor were decreased. Isotope separation coefficients for the hydrophobic PTFE membranes were 1.004∼1.01 depending on the experimental conditions. We observed the effects of air in membrane pores on the oxygen isotope separation. Isotope separation coefficients for the hydrophobic PTFE membranes without air in pores are higher than those for the membrane with air in pores.

• Korean Journal of Materials Research
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• v.30 no.12
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• pp.655-659
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• 2020

Hydrogen isotopes (i.e. deuterium and tritium) are supplied to the tokamak in the International Thermonuclear Experimental Reactor (ITER) fuel cycle. One important part of the ITER fuel cycle is the recycling of unused fuel back to the tokamak, as almost 99 % of fuel is unburned during fusion reaction. For this, cryogenic distillation has been used in the isotope separation system (ISS) of ITER, but this technique tends to be energy-intensive and to have low selectivity (typically below 1.5 at 24 K). Recently, efficient isotope separation by porous materials has been reported in the so-called quantum sieving process. Hence, in this study, hydrogen isotope adsorption behavior is studied using chemically stable ZIF-11. At low temperature (40 K ~ 70 K), the adsorption increases and the sorption hysteresis becomes stronger as the temperature increases to 70K. Molar ratio of deuterium to hydrogen based on the isotherms shows the highest (max. 14) ratio at 50 K, confirming the possibility of use as a potential isotope separation material.

• Journal of the Korean Chemical Society
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• v.45 no.3
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• pp.219-222
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• 2001

Separation of lithium isotopes was investigated by chemical ion exchange with a hydrous manganese(IV) oxide ion exchanger using an elution chromatography. The capacity of manganese(IV) oxide ion exchanger was 0.5 meq/g. The heavier lithium isotope was enriched in the solution phase, while the lighter isotope was enriched in the ion exchanger phase. The separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factor of $^6Li^+$-$^7Li^+$ isotope pair fractionation was 1.018.

• Bulletin of the Korean Chemical Society
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• v.22 no.6
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• pp.570-574
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• 2001

Magnesium isotope separation was investigated by chemical ion exchange with the 1-aza-12-crown-4 bonded Merrifield peptide resin using an elution chromatographic technique. The capacity of the novel azacrown ion exchanger was 1.0 meq/g dry resin. The heavier isotopes of magnesium were enriched in the resin phase, while the lighter isotopes were enriched in the solution phase. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assys. The separation factors of $^{24}Mg^{2+}$-$^{25}Mg^{2+}$, $^{24}Mg^{2+}$-$^{26}Mg^{2+}$, and $^{25}Mg^{2+}$-$^{26}Mg^{2+}$ were 1.008, 1.019, and 1.006, respectively.

• Mass Spectrometry Letters
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• v.4 no.4
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• pp.87-90
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• 2013

Isotope amount ratios of lead in a bronze sample have been successfully determined using multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS). Matrix separation conditions were tested and optimized using ion exchange chromatography with anion-exchange resin, AG1-X8, and sequential elution of the 0.5 M HBr and 7 M $HNO_3$ to separate lead from very high contents of copper and tin in bronze matrix. Mercury was also removed efficiently in the optimized separation condition. The instrumental isotope fractionation of lead in the MC-ICP-MS measurement was corrected by the external standard sample bracketing method using an external standard, NIST SRM 981 lead common isotope ratio standard followed by correction of procedure blank to obtain reliable isotope ratios of lead. The isotope ratios, $^{206}Pb/^{204}Pb$, $^{207}Pb/^{204}Pb$, $^{208}Pb/^{204}Pb$, and $^{208}Pb/^{206}Pb$, of lead were determined as $18.0802{\pm}0.0114$, $15.5799{\pm}0.0099$, $38.0853{\pm}0.0241$, and $2.1065{\pm}0.0004$, respectively, and the determined isotope ratios showed good agreement with the reference values of an international comparison for the same sample within the stated uncertainties

• Bulletin of the Korean Chemical Society
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• v.23 no.11
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• pp.1541-1544
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• 2002

The concentration of B in steels is important due to its influence on mechanical properties of steel such as hardenability, hot workability, and creep resistance. An analytical method has been developed to determine B in steel samples by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). National Institute of Standard and Technology Standard Reference Material (NIST SRM) 348a was analyzed to validate the analytical method. The steel sample was digested in a centrifuge bottle with addition of aqua regia and $^{10}B$ spike isotope. Sample pH was then adjusted to higher than 10 to precipitate most matrix elements such as Fe, Cr, and Ni. After centrifugation, the supernatant solution was passed through a cation exchange column to enhance the matrix separation efficiency. B recovery efficiency was about 37%, while matrix removal efficiency was higher than 99.9% for major matrix elements. The isotope dilution method was used for quantification and the determined B concentration was in good agreement with the certified value.

• Analytical Science and Technology
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• v.10 no.6
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• pp.403-407
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• 1997

Separation factor for $^6Li$ and $^7Li$ have been determined using ion exchange resin having 1,7,13-trioxa-4,10,16-triazacyclooctadecane($N_3O_3$) as an anchor group. The lighter isotope, $^6Li$ is concentrated in the solution phase, while the heavior isotope, $^7Li$ is enriched in the resin phase. By Ccolumnl chromatography[0.9cm(I.D)${\times}$20cm(height)] using 2.0M ammonium chloride solution as an eluent, single separation factor, ${\alpha}$, 1.009. i.e.$(^7Li/^6Li)_{resin}$/$(^7Li/^6Li)_{solution}$ was obtained by the Glueckauf theory from the elution curve and isotope ratios.