• Journal of the Korean Chemical Society
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• v.34 no.1
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• pp.69-75
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• 1990

An ion-association chromatography was applied for the separation and determination of individual rare earth elements (REE) contained in mineral monazite. Prior to the determination, the group separation of REE was achieved by a cation exchange column of Dowex 5OW-X8 resin. The quantitative recovery of REE by the resin column, free from coexisting elements in monazite, was confirmed with radioactive tracers as well as with ICP-MS. Individual REE at ppm level was separated on reversed-phase column ($\mu$-Bondapak $C_{18}$) using gradient elution from 0.05 to 0.3 M $\alpha$-hydroxyisobutyric acid at pH 4.6. The individual REE was detected at 546 nm following post-column reaction with PAR (4-(2-pyridylazo)-resorcinol monosodium salt).

• Analytical Science and Technology
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• v.7 no.2
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• pp.201-204
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• 1994

Cation exchange column chromatography of lithium was carried out to investigate the lithium isotope separation in aqueous ion exchange system. A Pyrex glass column of $50cm{\times}6mm$ inner radius with a water jacket was used as the separation column in experiment. Upon column chromatography using hydrochloric and succinic acid mixtures as an elunent, single separation factor, ${\alpha}$, 1.0068 was obtained. From the experiment, it was found that $^6Li$ was enriched in the resin phase and $^7Li$ in the solution phase.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.349-356
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• 2010

Ion chromatography (IC) coupled with conductivity detector (CD) is a common system for the determination of perchlorate in water samples. Although the IC method with CD has been widely used for the determination of trace level perchlorate ion in water, sensitivity decreases dramatically as the complexity of the matrices increases. Here we proposed the application of ion chromatography coupled with mass spectrometry (IC-MS/MS) to significantly improve selectivity of perchlorate. The mean recovery of the method was 104.4 ${\pm}$ 5.7% and the relative standard deviation (RSD%) was 1.9 ${\pm}$ 1.3%. The alculated method detection limit (MDL) was 0.0207 ${\pm}$ 0.0099 ${\mu}g/L$. The concentrations of perchlorate were minimum <0.1 ${\mu}g/L$ and maximum 18.3 ${\mu}g/L$ in source water (Namhan, Bukhan and Han River). Hongreung showed higher concentrations ($1^{st}$-14.3 ${\mu}g/L$, $2^{st}$-18.3 ${\mu}g/L$) than the other places. And the concentrations of perchlorate were 0.18~0.34 ${\mu}g/L$ in the samples taken from the six water treatment plants and six intake stations in Seoul.

• Analytical Science and Technology
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• v.8 no.3
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• pp.259-264
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• 1995

The separation efficiency of metal ions by using the poly-NTOE(1, 12-diaza-3, 4:9, 10-dibenzo-5, 8-dioxacyclopentadeca-1, 12-ylene-2, 7-dihydroxyoctamethylene) has been determined by column chromatography in aqueous solution. Binding constants and separation factors for several poly-NTOE interactions were measured in aqueous solution. The order of these binding constants and separation factors with metal ions were Co(II)Zn(II) for the transition metal ions and Cd(II)

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.450-454
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• 2023

Chloride ions in the alloy powder used as flux in Flux Cored Arc Welding (FCAW) can cause pores on the bead surface of the welding metal to cause defects, or chloride remaining in the alloy powder can cause corrosion of the metal. Combustion-ion chromatography is mainly used to quantify the chloride ions in alloy powder, but there is a limitation in that the equipment is expensive and requires a high degree of expertise. Therefore, this study aims to find an easy and accurate quantification method in the field by comparing combustion-ion chromatography (C-IC), which is mainly used for chloride ion quantification of alloy powder, X-ray fluorescence analysis (XRF), and potentiometric titration. In this article, magnesium-aluminum alloy powder is applied to the quantification of chloride ions because it is most commonly used as flux. This study confirmed that potentiometric titration can be applied to the quantification of chloride ions in the alloy powder in the industry field.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.259-264
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• 1993

• Journal of Radiation Protection and Research
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• v.26 no.1
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• pp.1-6
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• 2001

An accurate and rapid analytical technique of uranium isotopes in highly contaminated soil samples was developed and validated by application to the IAEA-Reference samples. For overcoming the demerits of the TBP extraction method, sample materials were decomposited with $HNO_3$ and HF, and uranium isotopes were purified by an anion exchange resin and a TRU Spec resin. With the extraction chromatography method, the hindrance elements were completely removed from the uranium fraction. The chemical yields with the extraction chromatography method were more 10% higher than those with the TBP extraction method. The concentrations of uranium isotopes in soil samples using the extraction chromatography method were consistent with the reference values reported by the IAEA.

• Analytical Science and Technology
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• v.17 no.1
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• pp.29-36
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• 2004

An analytical method of polybrominated diphenyl ethers in soil samples by isotope dilution method using gas chromatography/mass spectrometry (GC/MS)-selected ion monitoring (SIM) was described. PBDEs in soil were extracted with soxhlet extractor and then silica and florisil solid phase extraction (SPE) methods as purification of extract were compared. After clean-up, the extractions were analyzed by GC/MS with SIM mode. Quantitation was performed isotope dilution method using four $^{13}C$ isotopically labeled PBDEs as internal standards. This developed method was validated for eight congeners of PBDEs in the concentration range 0.04~4 ng/g in soil and the average recovery of the analytes ranged 30.8~110.8% for florisil and 44.4~110.7% for silica, respectively. The method detection limits of PBDEs were 0.04~0.3 ng/g.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.11a
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• pp.201-202
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• 2006

• Analytical Science and Technology
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• v.23 no.1
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• pp.45-53
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• 2010

For the determination of chlorine in uranium compound, analytical methods by using a steam distillation and a pyrohydrolysis have been developed. The steam distillation apparatus was composed of steam generator, distilling flask and condenser etc. The samples were prepared with an aliquot of LiCl standard solution and a simulated spent nuclear fuel. A sample aliquot was mixed with a solution containing 0.2 M ferrous ammonium sulfate-0.5 M sulfamic acid 3 mL, phosphoric acid 6 mL and sulfuric acid 15 mL. The chloride was then distilled by steam at the temperature of $140^{\circ}C$ until a volume of $90{\pm}5\;mL$ is collected. The pyrohydrolysis equipment was composed of air introduction system, water supply, quartz reaction tube, combustion tube furnace, combustion boat and absorption vessel. The chloride was separated from powdered sample which is added with $U_3O_8$ accelerator, by pyrohydrolysis at the temperature of $950^{\circ}C$ for 1 hour in a quartz tube with a stream of air of 1 mL/min supplied from the water reservoir at $80^{\circ}C$. The chlorides collected in each absorption solution by two methods was diluted to 100 mL and measured with ion chromatography to determine the recovery yield. For the ion chromatographic determination of chlorine in molten salt retained in a metal ingot, the chlorine was separated by means of pyrohydrolysis after air and dry oxidation, and grinding for the sample.