• Analytical Science and Technology
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• v.14 no.6
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• pp.530-534
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• 2001

Effect of stripping solutions on the Duolite GT-73 chelating resin for ten elements, Ag(I), Al(III), Ca(II), Cd(II), Cu(II), Fe(II), Hg(II), Mn(II), Pb(II), and Zn(II), was investigated. Relation between affinities of the metal ions and solubility products of metal sulfides was studied. The smaller the solubility product of metal sulfideis, the larger the affinitie with the ionsis. The ions which have the solubility products larger than $10^{-23}$ could be effectively desorbed with nitric acid. Complexation with chloride ion enhanced the desorption efficiencies of the ions having moderately strong affinity with the resin. The ions which have very strong affinity by the chelating resin can be desorbed by complextion with thiourea and hydrochloric acid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.85-96
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• 1988

Purification and some properties of alkaline proteinases in the pyloric caeca of skipjack, Katsuwonus vagans, were investigated. Four alkaline proteinases, temporarily designated proteinases I, II, III and IV, were identified from the tissue extract of the pyloric caeca by ammonium sulfate fractionation, DEAE-Sephadex A-50 chromatography, and Sephadex G-100 and G-200 gel filtration. Result of disc-polyacrylamide gel electrophoretic analysis showed that the purified proteinases II and III were homogenous with the yields of $1.5\%\;and\;1.2\%$, and those specific activities were increased to 33 to 37 fold over that of the crude enzyme solution, respectively. Molecular weight of the proteinases II and III determined by sephadex G-100 gel filtration were 28,500 and 24,200, respectively. The optimum conditions for the caseinolytic activity of the two enzymes were pH 9.6 and $48^{\circ}C$. The reaction rates of the two alkaline proteinases were constant to the reaction time to 80 min in the reaction mixture of $3.4{\mu}g/ml$ of enzyme concentration and $2\%$ casein solution. The Km values against casein substrate determined by the method of Lineweaver-Burk were $0.56\%$ for proteinase II and $0.30\%$ for proteinase II. The proteinases II and III were inactivated under the presence of $Ag^+,\;Hg^{2+},\;Ni{2+},\;Fe^{2+},\;and\;Cu^{2+}$, and but activated by $Mn^{2+}\;and\;Ca^{2+}$ and markedly inhibited by the soybean trypsin inhibitor and N-p-toluenesulfonyl-L-lysine chloromethyl ketone. Therefore, the proteinases II and III were found to be a group of serine proteases and assured to be trypsin-like proteinases.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.434-440
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• 2003

The powders of L $a_{0.8}$C $a_{0.2}$Mn $O_3$ Colossal Magnetoresistance (CMR) materials were synthesized by sol-gel process. Lanthanum(H), Calcium(II) and Manganese(III) 2,4-Pentanedionate were dissolved in a mixed binary solution consisted of propionic acid and methanol with PEG (15 wt%) aqueous solution. The progress of reactions was monitored by FT-IR spectroscopy. The Lao scao.2Mn03 gel powders were annealed at various temperatures. The structural changes were investigated by FT-IR, CP/MAS $^{ 13}$C solid state NMR spectroscopy and XRD. The thermochemical property, particle characterization, microstructure of sintered sample, and cation composition of gel powder were studied by TG/DTA, FE-SEM and ICP-AES. The magnetic characterizations were identified through measurement of magnetic moment by VSM.

• Analytical Science and Technology
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• v.17 no.1
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• pp.1-7
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• 2004

The synergistic solvent extraction of Mn(II) by N-nitroso-N-phenylhydroxylamineammonium salt (cupferron) and tetrabutylammonium ion ($TBA^+$) has been studied. In the presence of $TBA^+$, over 95% Mn(II) was extracted from an aqueous solution into chloroform by the cupferron in the pH range of 4 to 10. But a part of Mn(II) was extracted with only cupferron. The ternary complex of Mn(II) was more efficiently extracted into $CH_2Cl_2$ and $CHCl_3$ than other nonpolar solvents. The extracted Mn(II) was determined in the back-extracted $HNO_3$ solution by GF-AAS. This fixed procedure was applied to the determination of trace Mn(II) in tap water samples of pH 5.0. The detection limit equivalent to 3 times standard deviation of the background absorption was 0.37 ng/mL and Mn(II) was determined with the range of 0.4 to 1.01 ng/mL in our laboratory's tap water. And the recovery was 94 to 107% in samples in which 2.0 ng/mL Mn(II) was spiked. The interferences of common concomitant elements such as Cu(II), Ca(II), Fe(III) and so on were not shown up to $10{\sim}20{\mu}g/mL$. From these results, this procedure could be concluded to be applied for the determination of trace Mn(II) in other environmental water samples.

• Mass Spectrometry Letters
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• v.6 no.2
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• pp.43-47
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• 2015

Detection of mefenamic acid (M, non-steroidal anti-inflammatory drug, NSAIDs) and its metallodrug was investigated using electrospray ionization mass spectrometry (ESI-MS) and fluorescence spectroscopy. ESI-MS data (500 µL, 1×10-3 M) revealed high detection sensitivity for the drug and metallodrug. ESI-MS spectra revealed peaks at 242, 580, and 777 Da corresponding to [M+H]+, [63Cu(M-H)2(H2O)2+H]+, and [56Fe(M-H)3+H]+, respectively. The metal:mefenamic ratios of ESIMS spectra are in complete agreement with the fluorescence spectroscopy results (1:2 for Cu(II) and 1:3 for Fe(III)). ESI is a soft ionization technique that can be used on labile metallo-mefenamic acids and is promising for the detection of these species in environmental samples and biological fluids.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.67-82
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• 2002

Objectives: In recent years, extensive focus has been laid on adulteration of herbal medicine with heavy metals. This may be mainly due to soil contamination by environmental pollution. The objective of this study is to identify the contents of various heavy metals in the blood from Ohjeok-san (Wuji-san) Decoction (OD) treated-rats. Methods: For this study, 13 kinds of metals including essential and heavy metals, i.e. A1, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn were analyzed by a slight modification of EP A methods and the following results are obtained. Results: 1. There was no significant difference between the OD-treated groups and control group in liver, kidney, bone, brain and weight, especially no significant difference at the 5th and 10th days in weight and the amount of food intake. 2. The amount of each metal analyzed in the blood were as follows; A1: 2.3~3.07 mg/l, As: 2.90~3.66 mg/l, Cd: 0~0.001 mg/l, Co: 0~0.01 mg/l, Cr: 0.40~043 mg/l, Cu: 0.93~1.88 mg/l, Fe: 414.35~464.46 mg/l, Hg: 0.01 mg/l, Mn: 0.10~0.17 mg/l, Ni: 0.01 mg/l, Pb: 0.03~012 mg/l, Se: 0.73 mg/l, Zn: 3.41~4.13 mg/l by groups, respectively. In control and experimental group, Experimental I and other experimental II, III, IV, and V groups, there were no significant differences. 3. The amount of non-toxic metals (A1, Co, Cu, Fe, Mn, Se, Zn) were $64.1{\pm}7.71{\;}mg/l$ in the control group and 60.70~67.58 mg/l in the experimental groups I, II, III, IV and V. The amount of Toxic metals (As, Cd, Cr, Ag, Pb) were $0.68{\pm}0.21{\;}mg/l$ in the control group and 0.57 ~ 0.66mg/l in the experimental groups. The total amount of metals were 32.35 mg/l in the control group and 30.48~34.12 mg/l in the test groups I, II, III, IV and V, respectively. Conclusions: There was no significant difference of metal concentration in the blood from the OD-treated-rats compared to those of the control group even if higher dosage (1~8 times the dosage for a person) of OD was administered. This may be mainly due to a decoction treatment which contains only supernatants filtered from the herb-mass after boiling. This indicates the legal limitation for metal concentration in herbal medicine must be applied according to different treatment methods of herbal medicine.

• Economic and Environmental Geology
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• v.31 no.5
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• pp.375-388
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• 1998

The purpose of this study is to investigate the ore genesis and occurrence of the Wondong polymetallic mineral deposits. The Pb-Zn, Fe and W-Mo mineralizations are found in skarn zones which formed mainly in or along the fault shear zones with the $N25-40^{\circ}W$ and $N10-50^{\circ}E$ directions, whereas the Cu-Mo mineralization is appeared hydrothermal replacement zone. The skarn minerals consist mainly of garnet and epidote, which were the last alteration phases between pneumatolytic and hydrothermal stages. The mineral paragenesis toward the late stage are as follows: arsenopyrite, scheelite, magnetite, pyrite, pyrrhotite, sphalerite, galena, chalcopyrite and molybdenite. Average ore grades are 0.33 g/t Au, 46.29 g/t Ag, 0.06% Cu, 4.4% Pb, 2.61% Zn and 29.39% Fe in tunnels, and 0.31 % Cu, 0.52% Pb, 6.29% Zn, 29.29% Fe, 0.03% Mo and 0.12% $WO_3$ in drill cores. Fluid inclusion data shows that Type I (liquid-rich), Type II (vapor-rich) and Type III (halite-bearing) inclusions are coexisted and their homogenization temperatures are quite similar. This indicates that boiling conditions have been reached during the mineralization. It is also likely that the ore solutions were evolved through the mixing between magmatic and meteoric waters. Rhyolite and quartz porphyry far the mineralization probably are not responsible of the Wondong polymetallic mineral deposits.

• Journal of the Korean Chemical Society
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• v.9 no.1
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• pp.45-48
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• 1965

Stability constant, composition of copper (II)-oxamidoxime complex were determined by spectrophotometric method. The ratio of copper (II) and oxamidoxime in the above complex was 1 : 1, and its stability constant was calculated to be $2.4{\times}10^{22}$. The complex solution gave constant absorbancy between the pH range of 4.5 to 6 at 600 $m{\mu}$ in which Beer's law applicable in the concentration range of 0.3 to 2.0 ppm studied in this work. It was noted that some metals such as Fe(III), Ni(II), Co(II), U(VI) interfere copper determination by this method.

• Analytical Science and Technology
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• v.17 no.3
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• pp.199-210
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• 2004

A new polystyrene-divinylbenzene chelating resin containing 4,5-dihydroxy-naphthalene-2,7-disulfonic acid (chromotropic acid : CTA) as functional group has been synthesized and characterized. The sorption and desorption properties of this chelating resin for Cr(III) ion and Cr(VI) ion including nine metal bloodstain. As a results, FOB test kit could be effectively applied to identification of human blood at chelating resin was stable in acidic and alkaline solution. The Cr(VI) ion is selectively separated from Cr (III) ion at pH 2 and the maximum sorption capacity of Cr(VI) ion is 1.2 mmol/g. In the presence of anions such as $F^-$, $SO{_4}^{2-}$, $CN^-$, $CH_3COO^-$, $NO{_3}^-$, the sorption of Cr(VI) ion was reduced but anions such as $PO{_4}^{3-}$ and $Cl^-$ revealed no interference effect. The elution order of metal ions obtained from breakthrough capacity and overall capacity at pH 2 was Cr(VI)>Sn(II)>Fe(III)>Cu(II)>Cd(II)${\simeq}Pb(II){\simeq}Cr(III){\simeq}Mn(II){\simeq}Ni(II){\simeq}Al(III)$. Desorption characteristics for Cr(VI) ion was investigated with desorption agents such as $HNO_3$, HCl, and $H_2SO_4$. It was found that the ion showed high desorption efficiency with 3 M HCl. As the result, the chelating resin, XAD-16-CTA was successfully applied to separation and preconcentration of Cr (VI) ion from several metal ions in metal finishing works.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.196-197
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• 2003

전자의 스핀정보를 이용한 spintronics 기술이 발전하면서 상온 강자성 반도체에 대한 연구가 주목을 각광 받고 있다. 자성반도체에 대한 연구는 diluted magnetic semiconductor(DMS)에 대한 연구로 시작되었다 할 수 있다. 과거 DMS는 II-IV족 또는 III-V족 반도체에 Mn, Cr, Co, Fe 원소들을 도핑 시켜 제작하여 왔으나, 상온 이상에서 강자성 특성을 가지는 DMS을 제작하는 데는 실패하였다. 최근에 Dietl 팀이 mean field 이론을 이용하여 망간이 도핑된 ZnO가 실온이상의 Tc를 가질 수도 있을 것으로 예측하였다.