• Journal of Society of Preventive Korean Medicine
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• v.8 no.2
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• pp.81-98
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• 2004

1. The cell viability was determined by MTT method. Their cytotoxic activities against three cancer cell lines such as A549, MDA-MB-231 and SNU-C4 cell line were tested. Among them, The methanol extract of Saururus chinensis Baill. showed the strongest cytotoxic effect against SNU-C4 cells. These results suggest that the methanol extract of Saururus Chinensis Baill. possessed a potential antitumorous agent. 2. In vitro the antitoxic activity of ethanol extract of Saururus Chinensis Bail on NIH 3T3 fibroblasts was evaluate by the MTT (3-(4,5-dimethyl- thiazol-2-yl)-2,5-diphenyl-2H-tetra캐lium bromide) and SRB (sulforhodamine B protein) assays. The number of NIH 3T3 fibroblasts were increased and tend to regenerate. These results suggest that Saururus Chinensis Bail extract retains a potential antitoxic activity. 3. Complexation of Cd (II) ion with ligands such as quercetin has been determined by UV-vis spectrophotometric method in tris buffer solution at various pH. It was found that only 1 : 1 Cd-complex is formed by the interaction between catechol moiety in ring B and cadmium [Cd(II)] in aqueous solution. The spectral parameters for Cd-complex were determined by Beer's law at various pH. It has shown that 1 : 1 Cd-complex has a maximum absorbance and red shift by the alkaline pH.

• Analytical Science and Technology
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• v.10 no.6
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• pp.427-432
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• 1997

A selective method for the determination of iron(III) ion with a sodium dodecyl sulfate(SDS) modified glassy carbon electrode was proposed. It was based on the electrostatic attraction and complexation of the SDS modifier, $(DS^-)_n-Fe^{3+}$. The determination of iron(III) ion was performed by a differential pulse voltammetry(DPV), and the reduction peak potential of $(DS^-)_n-Fe^{3+}$ was +0.466(${\pm}0.002$)V vs. Ag/AgCl. For the determination of iron(III) ion, a linear calibration curve was obtained within the iron(III) ion concentration range of $0.50{\times}10^{-5}{\sim}10{\times}10^{-5}mol/L$, and the detection limit was $0.14{\times}10^{-5}mol/L$. $Cu^{2+}$, $Ni^{2+}$, $Co^{2+}$, $Pb^{2+}$, $Zn^{2+}$, and $Mn^{2+}$ showed little or no effect on the determination of iron(III) ion, respectively. But, ion such as each $CN^- $ and $SCN^-$ interfered seriously.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.266-271
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• 2007

Bisphenol A (BPA) has been widely used as a monomer for production of epoxy resins and polycarbonate plastics. The annual production of BPA exceeds 640,000 metric tons in worldwide. BPA, a suspected phenolic endocrine disrupter, is moderately soluble and frequently detected in industrial wastewater. To date, HPLC and GC has been used for BPA analysis. However, HPLC and GC-analysis need high operation lost, experts, and an elaborate pre-treatment of samples, and is difficult to apply on-time and mass analysis. Therefore, simple, mass and rapid detection of BPA in environments is necessary. In the present study, spectrophotometric method of BPA quantification was developed. Based on blue-color product formation with BPA and ferric chloride/ferricyanide under the optimized conditions, the standard curve was acquired $({\lambda}_{750}=0.061\;BPA\;[{\mu}M]+0.07155,\;R^2=0.992)$. Using an established method, the BPA contents in the soil extract, and different water samples and living products, including disposable syringe, cup and plastic tube, were analyzed. The results suggested that the method is useful for BPA determination from different massive samples. Since the BPA metabolites, nontoxic 4-hydroxyacetophenone or 4-hydroxybenzaldehyde, did not form blue-color product, this method is also useful to screen a microorganism for BPA bioremediation.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.451-459
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• 2010

The fluorescence detection of intracellular metal ions are high interest in the fields of organic molecular chemistry and cellular biology. This study was purposed to detection for mercury and zinc in the cell using fluorescent chemosensor (FS). FS exhibits a weak fluorescence, but emits strong fluorescence upon Zn$^{2+}$ complexation. The increased fluorescence of the 2FS/Zn$^{2+}$ can be quenched completely by addition of only 1 equiv of Hg$^{2+}$ with the formation of complex FS-Hg$^{2+}$. Four cell lines (LLC-MK2, Hela, HT29 and AMC-HN3) were used for fluorescence imaging by confocal microscope. The cell viability MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was evaluated after cell treatment of FS, Zn$^{2+}$, FS-Zn$^{2+}$, Hg$^{2+}$ on LLC-MK2 cell line. The cytotoxicity of FS was showed to viability over 80%. This study has shown that FS can be detected for selective imaging of Zn$^{2+}$ and Hg$^{2+}$ in living cells.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.601-607
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• 2003

We studied on preparation of nanoparticles modified surface using biodegradable polymer, poly(DL-lactide-co-glycolide) (PLGA). Two kinds of PLGA nanoparticles were prepared by a spontaneous emulsification solvent diffusion (SESD) method using cetyltrimethylammonium chloride (CTAC) and tetradecyltrimethylammonium bromide (TTAB) as a cationic surfactant and polyethylene glycol-block-polypropylene glycol copolymer (Lutrol F68) as a nonionic surfactant. Model protein was coated on the surface of nanoparticles by the ionic complexation. The model protein was that influenza vaccine ($H_3N_2,\;H_1N_1$, B strain) labeled with NHS-fluorescein. The sizes of cationic nanoparticles were 140-160 nm and the surface charges were 50-60 mV. The sizes of nonionic nanoprticles were 80-90 nm and the surface charge was -10 mV. After coating vaccine on the surface of nanoparticles, the sizes of cationic nanoparticles were increased to 380-400 nm and the size of nonionic nanoparticles was not increased. The amount of coated vaccine on the cationic nanoparticles was 22.73 ${\mu}g$/mg.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.881-887
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• 1993

A cobalt(II) ion-selective carbon-paste electrode (CPE) was constructed with ${\iota}$-sparteine. Cobalt(II) ion in aqueous solution was chemically deposited through the complexation with ${\iota}$-sparteine onto the CPE. The surface of CPEs were characterized by cyclic voltammetry and differential pulse voltammetry in an acetate buffer solution, separately. Exposure of the CPEs to an acid solution could regenerate surface to reuse it for the deposition. In more than 5 deposition / measurement / regeneration cycles, the response was reproducible and linear up to $5.0{\times}10^{-6}$M with linear sweep voltammetry. The peaks at 0.17V / 0.27V were correspond to the redox of Co(II)-SP complex deposited on CPE. The anodic peak of which appeared after scan over the cathodic peak of 0.17 V to more negative scan. In case of using the differencial pulse voltammetry (DPV), we have obtained the linear response $2.0{\times}10^{-7}$M with relative standard deviation ${\pm}5.6%$. The detection limit was $1.0{times}10^{-7}$M for 20 minutes of the deposition. We have also investigated the interference effect of various metal ions, which are expected to form the complex with the ligand on the electrode.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.23-31
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• 2006

carbon modified methods were used for the preconcentration and determination of copper in some real samples using the flame atomic absorption spectrometry. The copper ions was adsorbed quantitatively on the activated carbon due to their complexation with 4- amino-2, 3-dimethyl-1-phenyl-3-pyrazoline (ADMPP) or 4-(4- methoxybenzylidenimin) thiophenole (MBITP). The adsorbed copper on solid phase was eluted quantitatively using small amount of nitric acid. The influence of important parameters including pH, amount of carrier, flow rate, amount of activated carbon and type and concentration of eluting agent for obtaining maximum recovery were investigated. The methods based on ADMPP and MBITP at optimum conditions is linear over concentration range of 0.05-1.5 g mL-1 and 0.05-1.2 g mL-1 of copper with correlation coefficient of 0.9997 and 0.9994 and both detection limit of 1.4 ng mL-1, respectively. The preconcentration leads to enrichment factor of 310 and break through volume of 1550 mL for both ligands. The method has a good tolerance limit of interfering ion and a selectivity that has been successfully applied for the determination of copper content in real sample such as tap, spring, river and waste water.

• Journal of the Korea Concrete Institute
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• v.29 no.1
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• pp.65-75
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• 2017

C-S-H phase is the most abundant reaction product, occupying about 50~60% of cement paste volume. The phase is also responsible for most of engineering properties of cement paste. This is not because it is intrinsically strong or stable, but because it forms a continuous layer that binds together the original cement particles into a cohesive whole. The binding ability of C-S-H phase arises from its nanometer-level structure. In terms of chloride penetration in concrete, C-S-H phase is known to adsorb chloride ions, however, its mechanism is very complicated and still not clear. The purpose of this study is to examine the interaction between chloride ions and C-S-H phase with various Ca/Si ratios and identify the adsorption mechanism. C-S-H phase can absorb chloride ions with 3 steps. In the C-S-H phase with low Ca/Si ratios, momentary physical adsorption could not be expected. Physical adsorption is strongly dependent on electro-kinetic interaction between surface area of C-S-H phase and chloride ions. For C-S-H phase with high Ca/Si ratio, electrical kinetic interaction was strongly activated and the amount of surface complexation increased. However, chemical adsorption could not be activated for C-S-H phase with high Ca/Si ratio. The reason can be explained in such a speculation that chloride ions cannot be penetrated and adsorbed chemically. Thus, the maximum chloride adsorption capacity was obtained from the C-S-H phase with a 1.50 Ca/Si ratio.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.554-559
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• 2007

In order to improve the reactivity for the direct synthesis of dimethyl carbonate (DMC) using methanol and carbon dioxide, the various additives were used in the DMC synthesis using $Ce_{0.8}Zr_{0.2}O_2$ catalyst, and then effect of the additives was investigated. The various additives were molecular sieves 3A and the compounds having the various functional groups such as sulfate, carbonate, nitrate and phosphate. As a result, the compound such as $K_2SO_4$ and $Na_2SO_4$ having sulfate group were the most effective additive among the various additives. When $K_2SO_4$ was used as an additive in the direct synthesis of DMC, the amount of DMC was about 0.91 mmol, which was the highest mount of DMC among using only-$Ce_{0.8}Zr_{0.2}O_2$ catalyst and the various additives.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.38-45
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• 2011

The complexation behavior of the $\alpha$-ketostabilized phosphorus ylides $Ph_3P$=CHC(O) $C_6H_4-X$ (X=Br, Ph) towards the transition metal ions mercury (II) and Silver (I) was investigated. The mercury(II) complex {$HgX_2$ [Y]} 2 ($Y_1$=4-bromo benzoyl methylene triphenyl phosphorane; X=Cl(1), Br(2), I(3), $Y_2$=4-phenyl benzoyl methylene triphenyl phosphorane; X=Cl(4), Br(5), I(6)) have been prepared from the reaction of $Y_1$ and $Y_2$ with $HgX_2$ (X=Cl, Br, I) respectively. Silver complexes [$Ag(Y_2)_2]$ X(X=$BF_4$(7), OTf(8)) of the $\alpha$-keto-stabilized phosphorus ylides ($Y_2$) were obtained by reacting this ylide with AgX (X=$BF_4$, OTf) in $Me_2CO$. The crystal structure of complexes (1) and (4) was discussed. These reactions led to binuclear complexes C-coordination of ylide and trans-like structure of complexes $[Y_1HgCl_2]_2$. $CHCl_3$ (1) and $[Y_2HgCl_2]_2$ (4) is demonstrated by single crystal X-ray analyses. Not only all of complexes have been studied by IR, $^1H$ and $^{31}P$ NMR spectroscopy, but also complexes 1-3 have been characterized by $^{13}$CNMR.