• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.138-138
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• 2006

• Bulletin of the Korean Chemical Society
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• 제22권5호
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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.

• The Korean Journal of Ceramics
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• 제6권3호
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• pp.309-314
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• 2000

In the present study, preliminary experimental results of the change in the properties of perovskite-type oxides caused by the $^{18}O$- exchange have been reported. Two systems were selected for the exchange, (1) $ATiO_3$(A=Ca,Sr,Ba) and (2) manganese perovskite. The dielectric properties of isotope-exchanged $SrTi^{18}O_3$showed a drastic change from a quantum paraelectricity below 3K to ferroelectric-like behavior with a peak at 23K and an enhanced dielectric constant, 35000 at the peak. On the contrary, the $T_c$ for $BaTiO_3$was found to increase by 0.9K. The observed isotope shift of $T_c$ as well as $T_co$ for the manganese perovskites is correlated with the key parameters controlling the lattice such as $Mn^{3+}$ content, average ionic radius of the A-site cation <$r_A$> ad A-site ionic disorder $\sigma^2$.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2959-2962
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• 2013

As the concentration of aqueous $CD_3OH$ solutions was decreased, the OD peaks in $^2H$ NMR spectra grew relative to the $CD_3$ peaks. Isotope impurity for OH groups of $CD_3OH$ and deuterium naturally present in water contributed to the OD peaks. Using these peak area data, the site-specific isotope populations of isotope enriched chemicals were measured. In addition, the method using both $^1H$ and $^2H$ NMR spectroscopy was demonstrated with neat $CD_3OH$ to measure the site-specific isotope populations. The results indicate that although it represents only ~0.015% of hydrogen isotopes, the deuterium naturally present in solvents cannot be ignored, especially when the concentration of deuterium-enriched solutes is varied. Proton/deuteron exchange between methyl and methyl/hydroxyl groups was confirmed to be negligible, while that among hydroxyl groups was detectable.

• Mass Spectrometry Letters
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• 제4권4호
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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

• 분석과학
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• 제10권6호
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• pp.403-407
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• 1997

Anchor group으로서 1,7,13-trioxa-4,10,16-triazacyclooctadecane($N_3O_3$)을 가지고 있는 이온교환수지를 사용하여 $^6Li$와 $^7Li$의 분리인자를 측정하였다. 가벼운 동위원소 $^6Li$는 액상에, 무거운 동위원소 $^7Li$는 이온교환수지상에 농축되었다. 2.0M 염화암모늄 용액을 용리액으로 사용한 컬럼 [0.9cm(내경)${\times}$20cm(높이)] 크로마토그래피에 의하여, 1.009의 분리인자, ${\alpha}$, $(^7Li/^6Li)_{resin}$/$(^7Li/^6Li)_{solution}$값을 얻었다. 이 값은 용리곡선과 동위원소비로부터 Glueckauf 이론을 적응하여 얻은 것이다.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2570-2575
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• 2021

The exchange behaviors of hydrogen isotopes between protonated lithium metal compounds and deuterated water or tritiated water were investigated. The various protonated lithium metal compounds were prepared by acid treatment of lithium metal compounds with different crystal structures and metal compositions. The protonated lithium metal compounds could more effectively reduce the deuterium concentration in water compared with the corresponding pristine lithium metal compounds. The H⁺ in the protonated lithium metal compounds was speculated to be more readily exchangeable with hydrons in the aqueous solution compared with Li⁺ in the pristine lithium metal compounds, and the exchanged heavier isotopes were speculated to be more stably retained in the crystal structure compared with the light protons. When the tritiated water (157.7 kBq/kg) was reacted with the protonated lithium metal compounds, the protonated lithium manganese nickel cobalt oxide was found to adsorb and retain twice as much tritium (163.9 Bq/g) as the protonated lithium manganese oxide (69.9 Bq/g) and the protonated lithium cobalt oxide (75.1 Bq/g) in the equilibrium state.

• 대한방사성의약품학회지
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• 제8권2호
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• pp.71-76
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• 2022

Indigenous diagnostic dose of ¹³¹I-labeled meta-iodobenzylguanidine ([¹³¹I]mIBG) was prepared via Cu⁺ catalyzed isotope exchange reaction generated in situ by sodium metabisulfite for imaging of neuroblastoma tumor. [¹³¹I]mIBG was produced in overall 85-90% radiochemical yield. The average amount of radioactivity of [¹³¹I]mIBG was 2164 MBq (1998-2331MBq) with an average specific activity > 1000 MBq/mg at the end of synthesis. The radiochemical purity was ≥ 99.9% after purification through Dowex-1 × 8 ion exchange resin (100-150 mesh) at the date of preparation. The stability of [¹³¹I]mIBG at concentration 480-555 MBq/mL was > 97% at 4 ℃ after 4 days. The room temperature (25 ℃) stability of [¹³¹I]mIBG was > 98% after 24 h. Biodistribution of [¹³¹I]mIBG in patient showed uptake in salivary glands, liver, spleen and excreted though urinary bladder. Neuroendocrine medicated uptake into tumor lesion and metastatic sites were noted which strongly correlate with the morphological abnormalities of patient.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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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.

• 분석과학
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• 제11권4호
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• pp.231-234
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• 1998

$N_3O_3$가 앵커 그룹으로 포함된 이온교환체를 사용하여 $^6Li$와 $^7Li$의 분리인자를 측정하였다. 이온교환체의 이온교환 용량은 2.0 meq/g 이었다. 3M 염화암모늄 수용액을 용리액으로 하였으며, 내경 0.3 cm, 높이 30 cm의 칼럼을 이온교환크로마토그래피에 사용하였다. 가벼운 동위원소 $^6Li$는 유체상에, 무거운 동위원소 $^7Li$는 수지상에 농축되었다. 용리곡선과 동위원소 비를 가지고 Glueckauf의 이론에 따라 분리인자를 구하였으며, 그 값은 1.018이었다.