• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3482-3488
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• 2014

Matrix-induced mass bias and its effect on the accuracy of isotope ratio measurements have been examined for a quadrupole-based inductively coupled plasma-mass spectrometer (Q ICP-MS). Matrix-induced mass bias effect was directly proportional to % mass difference, and its magnitude varied for element and nebulizer flow rate. For a given element and conditions in a day, the effect was consistent. The isotope ratio of Cd106/Cd114 under $200{\mu}g\;g^{-1}$ U matrix deviated from the natural value significantly by 3.5%. When Cd 111 and Cd114 were used for the quantification of Cd with isotope dilution (ID) method, the average of differences between the calculated and measured concentrations was -0.034% for samples without matrix ($0.076{\mu}g\;g^{-1}$ to $0.21{\mu}g\;g^{-1}$ for the period of 6 months). However, the error was as large as 1.5% for samples with $200{\mu}g\;g^{-1}$ U. The error in ID caused by matrix could be larger when larger mass difference isotopes are used.

• Korean Journal of Materials Research
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• v.16 no.2
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• pp.80-84
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• 2006

The removal efficiency of Cu and Fe contaminants on the silicon wafer surface was examined to investigate the effect of cleaning solutions on the behavior of metallic impurities. Silicon wafers were intentionally contaminated with Cu and Fe solutions by spin coating and cleaned in different types of cleaning solutions based on $NH_4OH/H_2O_2/H_2O\;(SC1),\;H_2O_2/HCl/H_2O$ (SC2), and/or HCl/$H_2O$ (m-SC2) mixtures. The concentration of metallic contaminants on the silicon wafer surface before and after cleaning was analyzed by vapor phase decomposition/inductively coupled plasma-mass spectrometry (VPD/ICP-MS). Cu ions were effectively removed both in alkali (SC1) and in acid (SC2) based solutions. When $H_2O_2$ was not added to SC2 solution like m-SC2, the removal efficiency of Cu impurities was decreased drastically. The efficiency of Cu ions in SC1 was not changed by increasing cleaning temperature. Fe ions were soluble only in acid solution like SC2 or m-SC2 solution. The removal efficiencies of Fe ions in acid solutions were enhanced by increasing cleaning temperature. It is found that the behavior of metallic contaminants as Cu and Fe from silicon surfaces in cleaning solutions could be explained in terms of Pourbaix diagram.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3362-3366
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• 2013

A simple and quick separation technique for selenite in natural water was developed using $TiO_2$@$SiO_2/Fe_3O_4$ nanoparticles. For the synthesis of nanoparticles, a polymer-assisted sol-gel method using hydroxypropyl cellulose (HPC) was developed to control particle dispersion in the synthetic procedure. In addition, titanium butoxide (TBT) precursor, instead of the typical titanium tetra isopropoxide, was used for the formation of the $TiO_2$ shell. The synthesized nanoparticles were used to separate selenite ($Se^{4+}$) in the presence of $Se^{6+}$ or selenium anions for the photocatalytic reduction to $Se^0$ atom on the $TiO_2$ shell, followed by magnetic separation using $Fe_3O_4$ nanoparticles. The reduction efficiency of the photocatalytic reaction was 81.4% at a UV power of 6W for 3 h with a dark adsorption of 17.5% to the nanoparticles, as determined by inductively coupled plasma-mass spectrometry (ICP-MS). The developed separation method can be used for the speciation and preconcentration of selenium cations in environmental and biological analysis.

• Analytical Science and Technology
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• v.24 no.3
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• pp.159-167
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• 2011

In this study, the hydride vapour generator inductively coupled plasma mass spectrometry (HVGICPMS) was applied as the new analytical method to show the high accurate and reproductive data analysing the amounts of selenium and germanium being existed inside a system of plant. In order to decrease the interference effects, such as ion and molecular interference. Mini torch was used into the ICPMS instead of the conventional torch. At conditions of the different kinds and concentrations of acid solution, the different reductive conditions for composing hydride, and the different methods for making ash, the contents of selenium and germanium in lettuce were analysed. The inspection of yields and data comparison from SRM-1574 and -1570a were used for increasing the accuracy of this analysis.

• The Journal of the Petrological Society of Korea
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• v.13 no.4
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• pp.238-243
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• 2004

Duwon meteorite was fallen on 23 November 1943 in Duwonmyeon, Goheung, Jeolanam-Do. We measured rare earth element abundance of Duwon meteorite by isotope dilution thermal ion mass spectrometry (ID-TIMS) and ICP-MS. As a result, except La and Ce, abundance of other rare earth element show a correspondence within 10％ of error range. However, La and Ce show more than 70％ in abundance, which is considered due to 1) experimental procedure or 2) inhomogeneity of sample. Leedey meteorite was fallen on 25 November 1943 in Dewey County, Oklahoma, USA. which suggested that fallen difference between Leedey and Duwon meteorites is only 2 days. Leedey and Duwon meteorites are classified as ordinary chondrite of L6 type. In Leedey chondrite-normalized REE pattern, Duwon meteorite shows nearly flattened, which suggests close relationship between Leedey and Duwon meteorites meteoritically or cosmochemically.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1985-1992
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• 2007

Ordered mesoporous silica (MCM-41) materials with different textural properties were prepared using alkyl (dodecyl, cetyl, eicosane) trimethyl ammonium bromide (DTAB, CTAB, ETAB, respectively) as structure directing surfactants, functionalized with amine groups and used as adsorbent for the toxic metal ions, Cr (VI), As (V), Pb (II) and Hg (II). Amino functionalization of mesoporous MCM-41 was achieved by cocondensation of N-[3-(trimethoxysilyl)-propyl] aniline with tetraethyl orthosilicate. Adsorption isotherm and adsorption capacity of the amine functionalized materials for Cr (VI), As (V), Pb (II) and Hg (II) ions were followed by inductively coupled plasma mass spectrometry (ICP-MS). Results demonstrate that amine functionalized MCM-41 prepared with ETAB showed higher adsorption capacity for Cr (VI), As (V), Pb (II) and Hg (II) ions in comparison to MCM-41 prepared with CTAB and DTAB. The higher adsorption capacity for MCM-41(ETAB) was correlated with amine content in the material (determined by CHN analysis) and relative decrease in pore volume and pore diameter. X-ray diffraction (XRD) analysis, nitrogen adsorptiondesorption measurements and Fourier Transform infrared spectrometry (FTIR) were used to follow the changes in the textural parameters and surface properties of the mesoporous materials as a result of amine functionalization to correlate with the adsorption characteristics. The adsorption process was found to depend on the pH of the medium.

• Restorative Dentistry and Endodontics
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• v.39 no.2
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• pp.89-94
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• 2014

Objectives: The aim of this study was to evaluate the cytotoxicity, setting time and compressive strength of MTA and two novel tricalcium silicate-based endodontic materials, Bioaggregate (BA) and Biodentine (BD). Materials and Methods: Cytotoxicity was evaluated by using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide (XTT) assay. Measurements of 9 heavy metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) were performed by inductively coupled plasma-mass spectrometry (ICP-MS) of leachates obtained by soaking the materials in distilled water. Setting time and compressive strength tests were performed following ISO requirements. Results: BA had comparable cell viability to MTA, whereas the cell viability of BD was significantly lower than that of MTA. The ICP-MS analysis revealed that BD released significantly higher amount of 5 heavy metals (arsenic, copper, iron, manganese, and zinc) than MTA and BA. The setting time of BD was significantly shorter than that of MTA and BA, and the compressive strength of BA was significantly lower than that of MTA and BD. Conclusions: BA and BD were biocompatible, and they did not show any cytotoxic effects on human periodontal ligament fibroblasts. BA showed comparable cytotoxicity to MTA but inferior physical properties. BD had somewhat higher cytotoxicity but superior physical properties than MTA.

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.405-416
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• 2018

In this research, the distribution of Platinum Group Elements (PGEs) at roadside dust in Daejeon, Korea was examined using an ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) technique. For the quality assurance of the determination, method validation based on its accuracy and precision was conducted using SRM (Standard Reference Material). It was found that the relative errors of Pt, Pd, and Rh against each SRM value were -0.7%, -10.0%, and -20.4%, respectively, while relative standard deviations for three elements were less than 10%. The concentrations of Pt, Pd and Rh in roadside dust averaged as $17.4{\pm}9.2{\mu}g/kg$, $283.6{\pm}20.5{\mu}g/kg$, and $7.3{\pm}2.8{\mu}g/kg$, respectively. The concentrations of Pt and Rh have significantly higher distribution patterns in the dust at roadside and underground parking lot than those in soil of the background or other urban area. The correlation analysis between concentrations of PGEs in roadside dust indicates that the distribution of Pt and Rh concentration were strongly affected by automobile sources.

• Analytical Science and Technology
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• v.26 no.2
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• pp.135-141
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• 2013

The purpose of this study is to determine the quantity of selenium in grains by hydride generation-inductively coupled plasma mass spectrometry. Two sample preparation methods, beaker and microwave digestions, are compared and the former shows better result. The optimum condition for hydride generation is 4.0 M for HCl, 3% for $NaBH_4$ with the sample flow of 0.6 mL/min. The detection limit is 0.02 ${\mu}g/kg$($3{\sigma}$) and improved by 10 times. Isobaric interferences on Se is removed by Octopole Reactoin Cell and $H_2$ (3.8 mL/min) shows better performance over He. However, in case Br exists in a matrix, $H_2$ could induce interferences on m/z 80 and 82 ($^{80}[BrH]^+$ and $^{82}[BrH]^+$). The accuracy of this experiment is examined successfully by analyzing several reference materials. The results for several domestic grain analysis show that the concentrations are between 12.7 ${\mu}g/kg$ and 29.6 ${\mu}g/kg$.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.18-23
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• 2006

Purpose : The reliability of hair mineral analyses regarding nutritional status, environmental exposure or diseases is controversial. The aim of this study was to determine the normal reference range of hair mineral concentration of Korean children. Methods : We examined hair mineral concentrations of 223 children(3-12 yrs old, 110 boys, 113 girls, mean age $8.8{\pm}2.2$ yrs old) living in the northern area of Seoul. The trace elements including six toxic elements(Al, As, Cd, Ba, Hg, Pb) and 11 nutritional elements(Na, Mg, P, K, Ca, Cr, Mn, Fe, Cu, Zn, Se) were analyzed by inductive coupled plasma mass spectrometry(ICP-MS). Results : The mean concentrations of Ca and Mg were higher in girls than in boys. The mean concentrations of Cd, Pb and Cr were higher in boys than girls. The Zn, Ca, Mg, Cu and Hg levels in hair samples were positively correlated with increasing age. The Zn levels of the Korean children's hair samples appear to be lower than that of other countries' reference values. Conclusion : There are considerable differences in hair mineral concentrations by age, sex and race. Additional research is needed to establish Korean reference values, and to evaluate the usefulness of hair mineral analyses as a screening tool for nutrition- and environment-related childhood diseases.