• Analytical Science and Technology
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• v.9 no.4
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• pp.364-372
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• 1996

The sorption and desorption properties of U(VI), Th(IV), Zr(IV), Cu(II), Pb(II), Ni(II), Zn(II), Cd(II) and Mn(II) ions on XAD-16-[2-(2-thiazolylazo)-p-cresol](TAC) chelating resin were studied by elution method for selective separation, concentration and recovery of trace metal ions in sea water. The optimum conditions for the sorption of metal ions were examined with respect to flow rate, pH and concentration of buffer solution. The overall capacities of some metal ions on this chelating resin were 0.41mmol U(VI)/g resin, 0.55mmol Th(IV)/g resin, 0.43mmol Cu(II)/g resin, and 0.32mmol Zr(IV)/g resin, respectively. The elution order of metal ions obtained from breakthrough capacity and overall capacity at pH 5.0 was found as Th(IV)>Cu(II)>U(VI)>Zr(IV)>Pb(II)>Ni(II)>Zn(II)>Cd(II)>Mn(II). Desorption of characteristics for metal ions were investigated with desorption agents such as $HNO_3$, HCl, $HClO_4$, $H_2SO_4$, and $Na_2CO_3$. It was found that most of metal ions except Zr(IV) showed high desorption efficiency with 2M $HNO_3$. But, desorption and recovery of Zr(IV) ion were successfully performed with 1M $H_2SO_4$. The resin was applied for separation and preconcentration of trace amount of U(VI) ion from artificial sea water and the recovery of U(IV) was over 96%.

• Analytical Science and Technology
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• v.31 no.6
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• pp.240-246
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• 2018

The present study analyzed standard samples of three types of aluminum matrix certified reference materials (CRM) using GD-MS. Calibration curves were constructed for 13 elements (Mg, Si, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Sn, and Pb), with the slope representing the relative sensitivity factor (RSF). The x- and y-axes of the calibration curve represented ion beam ratio (IBR) and the authenticated value of the standard sample, respectively. In order to evaluate precision and linearity of the calibration curve, RSD and the coefficient of determination were calculated. Curve RSD for every element reflected high precision (within 10 %). For most elements, the coefficient of determination was ${\geq}0.99$, indicating excellent linearity. However, vanadium, nickel, and gallium curves exhibited relatively low linearity (0.90~0.95), likely due to their narrow concentration ranges. Standard RSF was calculated using the slope of the curve generated for three types of CRM. Despite vanadium, nickel, and gallium exhibiting low coefficients of determination, their standard RSF resembled that of the three types of CRM. Therefore, the RSF method may be used for element quantitation. Standard iron matrix samples were analyzed to verify the applicability of the aluminum matrix standard RSF, as well as to calculate the RSD-estimated error of the measured value relative to the actual standard value. Six elements (Al, Si, V, Cr, Mn, and Ni) exhibited an RSD of approximately 30 %, while the RSD of Cu was 77 %. In general, Cu isotopes are subject to interference: $^{63}Cu$ to $^{54}Fe^{2+}-^{36}Ar$ and $^{65}Cu$ to $^{56}Fe-Al^{3+}$ interference. Thus, the influence of these impurities may have contributed to the high RSD value observed for Cu. To reliably identify copper, the resolution should be set at ${\geq}8000$. However, high resolutions are inappropriate for analyzing trace elements, as it lowers ion permeability. In conclusion, quantitation of even relatively low amounts of six elements (Al, Si, V, Cr, Mn, and Ni) is possible using this method.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.665-676
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• 2003

To investigate the chemical characteristics of PM$\_$2.5/ in Seoul, Korea, atmospheric particulate matters were collected using a PM$\_$10/ dichotomous sampler including PM$\_$10/ and PM$\_$2.5/ inlet during the period of October 2000 to September 2001. The Inductively Coupled Plasma-Mass Spectromety (ICP-MS), ion Chromatography (IC) methods were used to determine the concentration of both metal and ionic species. A statistical analysis was performed for the heavy metals data set using a principal component analysis (PCA) to derived important factors inherent in the interactions among the variables. The mean concentrations of ambient PM$\_$2.5/ and PM/sub10/ were 24.47 and 45.27 $\mu\textrm{g}$/㎥, respectively. PM$\_$2.5/ masses also showed temporal variations both yearly and seasonally. The ratios of PM$\_$2.5/PM$\_$10/ was 0.54, which similar to the value of 0.60 in North America. Soil-related chemical components (such as Al, Ca, Fe, Si, and Mn) were abundant in PM$\_$10/, while anthropogenic components (such as As, Cd, Cr, V, Zn and Pb) were abundant in PM2s. Total water soluble ions constituted 30∼50 % of PM$\_$2.5/ mass, and sulfate, nitrate and ammonium were main components in water soluble ions. Reactive farms of NH$_4$$\^$+/were considered as NH$_4$NO$_3$ and (NH$_4$)$_2$SO$_4$ during the sampling periods. In the results of PCA for PM$\_$2.5/, we identified three principal components. Major contribution to PM$\_$2.5/ seemed to be soil, oil combustion, unidentified source. Further study, the detailed interpretation of these data will need efforts in order to identify emission sources.

• Food Science and Preservation
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• v.21 no.4
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• pp.520-528
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• 2014

The purpose of this study was to evaluated a phthalate, heavy metal contents and physicochemical quality properties in korean mudflat solar salt and foreign salts. DEHP in mudflat solar salt (MSS) was detected a low level (9.00~669.89 ppb), but it was shown a high level excess to 1.5 ppm criteria in the foreign solar salt (FSS) 5 type (3,440.64, 3,266.56, 2,189.65, 4,010.69, 4,554.20 ppb) and foreign large solar salt (FLSS) 1 type (1,983.27 ppb). Also, DEHP in FSS 2 type (930.15, 1,310.07 ppb) and FLSS 1 type (924.92 ppb) was detected a high level not excess to criteria. No detected DMP, DEP, DIBP, DBP, DAP, BBP, DCHP and DEHA contents in MSS and foreign salt (FS). Na ion was shown a significantly higher level (p<0.05) in FS (407,345.87~426,612.14 ppm) than in MSS (363,633.98 ppm), but it was shown a high level in Mg (p<0.01), K (p<0.05), Ca ion (p<0.05) of FSS compared to foreign refined salt (FRS). Cl ion (532,727.07 ppm) of MSS was the most low level (p<0.001) compared to FS, but it was shown a high level (p<0.001) in Br ion (625.07 ppm). $SO_4$ ion was not shown a significant difference in DS and FS. It was display a high level in Mn of MSS, and Al, Fe of FLSS. Heavy metal contents (As, Cd, Pb and Hg) in MSS and FS was not significant difference, it was safety level as edible salt.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.41-48
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• 2004

Cyclodextrin glucanotransferase (CGTase) of Bacillus sp. isolated from soil was purified and its enzymological characteristics were investigated. It was found that the production of CGTase reached to the maximum when the strain was cultured in the broth containing 0.1 % albumin, 2% $NH_4Cl$, 2% soluble starch and 0.2% $NH_2PO_4$ for 72 hrs at $37^{\circ}C$. The purity of CGTase was increased by 9.7 folds through purification procedures by the following column chromatography DEAE-cellulose ion exchange chromatography and Sephadex G-100, G-150 gel filtration and its specific activity was 528.0 unit/mg. The optimum pH and temperature for the CGTase activity were 8.0 and $80^{\circ}C$, respectively. The enzyme was stable in pH $8.0{\sim}11.0$ at $60{\sim}80^{\circ}C$. The activity of purified enzyme was inhibited by $Pb^{2+},\;Hg^{2+}$ and $Zn^{2+}$. When CGTase was treated with each 20.5 unit, 41 unit, 205 unit and 410 unit to investigate the transglucosylation to stevioside by purified cyclodextrin glucanotransferase, transglucosylation rate to stevioside was 74.9%, 75.7%, 68.7% and 57.9%. Brown effect was observed above the concentration amounting to 205 unit of our CGTase.

• Journal of the Korean Ceramic Society
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• v.40 no.4
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• pp.323-327
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• 2003

Microwave dielectric properties of (P $b_{0.4}$C $a_{0.6}$)[($Fe_{\frac{1}{2}}$N $b_{\frac{1}{2}}$)$_{1-x}$ (M $g_{1}$ 3/N $b_{2}$ 3/)x] $O_3$ (PCFMN) ceramics were investigated as a function of (M $g_{1}$ 3/N $b_{2}$ 3/)$^{4+}$ content (0.1$\leq$x$\leq$0.8). A single perovskite phase with the cubic structure was obtained through the given composition range. The unit cell volume was increased with (M $g_{1}$ 3/N $b_{2}$ 3/)$^{4+}$, due to the larger average ionic size of (M $g_{1}$ 3/N $b_{2}$ 3/)$^{4+}$ than that of ($Fe_{\frac{1}{2}}$N $b_{\frac{1}{2}}$)$^{4+}$ for B-site ion. Dielectric constant (K) and Temperature Coefficient of Resonant Frequency(TCF) of PCFMN ceramics were dependent on (M $g_{1}$ 3/N $b_{2}$ 3/)$^{4+}$ content due to the decrease of ionic polarizability and B-site bond valence, respectively. Qf value was decreased with (M $g_{1}$ 3/N $b_{2}$ 3/)$^{4+}$ content due to the decrease of grain size. Typically, K of 73.56, Qf of 5,074 GHz and TCF of -6.45 ppm/$^{\circ}C$ were obtained for the specimens with x=0.4 sintered at 125$0^{\circ}C$ for 3 h.125$0^{\circ}C$ for 3 h.

• KSBB Journal
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• v.23 no.5
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• pp.425-430
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• 2008

Hydrogen sulfide ($H_2S$) is a by-product of metabolism of amino acids including sulfur and alcoholic fermentation, it is generally thought of in terms of a poisonous gas. Though $H_2S$ can have a negative impact on the perceived quality of fermented drinks due to an undesirable aroma, it plays prominent roles as a neuromodulator in the mammalian brain as well as a smooth muscle relaxant. Nowadays studies on the proteins which produce $H_2S$ are carried out in various fields such as structure, function, and metabolism. Here we propose to develop a simple and rapid $H_2S$ forming assay method, which will lead to speed up preparing the $H_2S$ forming proteins for identification by MALDI-TOF MS analysis. We detected three kinds of proteins which produce $H_2S$ in the crude extract of Saccharomyces cerevisiae. Those proteins were cystathionie $\beta$-synthase, O-acetylserine sulfhydrylase, and cystathionine $\gamma$-lyase.

• Economic and Environmental Geology
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• v.46 no.5
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• pp.391-409
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• 2013

The Hongseong area of the southwestern Gyeonggi massif is considered to be part of suture zone that is tectonically correlated with the Qinling-Dabie-Sulu belt of China in terms of the preservation of collisional evidences during Triassic in age. The Wolhyeonri complex, preserved at the center of the Hongseong area, consists mainly of Neoproterozoic orthogneisses and Middle Paleozoic intermediate- to high-grade metamorphic schists, orthogneisses and mafic metavolcanics. The area includes various Middle to Late Triassic intrusives (e.g. dyke or stock). They are mainly monzonite and aplite with small intrusions of monzodiorit, syenite and diorite in composition. The SHRIMP U-Pb zircon ages yield 237 Ma to 222 Ma. The geochemistry of the studied Triassic intrusives show similar subuction- or arc-type signatures having Ta-Nb troughs, depletion of P and Ti, and enrichment of LILEs (large ion lithophile elements). In addition, the Triassic plutons in the Hongseong area, including those from this study, mostly possess high-K calc-alkaline to shoshonitic tectonic affinity. These results could be tectonically correlated to the post-collisional magmatic event following the Triassic collision between the North and South China blocks in China. Therefore, the Triassic plutons in the Hongseong area offer an important insight into the Triassic geodynamic history of the NE Asian region.

• Microbiology and Biotechnology Letters
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• v.4 no.4
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• pp.131-137
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• 1976

Aspergillus niger S-1 was proved to be a good hesperidinase producer which have been selected for naringinase utilization. Enzyme of this strain had good characteristics and purified relative high degree with good recovery by ammonium sulfate or aceton treatment. Results obtained were summarized as follows (1) The enzyme was most active at 60$^{\circ}C$, when the reaction was performed in the pH 4.0 for 30min. Optimum pH for enzyme activity was 5.0 and activity was retained 78％ at pH value 3.5. (2) Hesperidinase activity retained 95％ of its full activity after treatment at 60$^{\circ}C$ for 30min at pH value 4.0., 70％ at 70$^{\circ}C$ and 65％ at 80$^{\circ}C$. Most stable pH of this enzyme was showed 5.0 after treatment for 24hr at 4$^{\circ}C$ (3) Only Magnesium ion activated enzyme reaction, while other metallic ions, Cu$\^$＋＋/, Mn$\^$＋＋/, Pb$\^$＋＋/, Mo$\^$＋＋/, Ag$\^$＋＋/, Hg$\^$＋＋/ inhibited. (4) Eleven fold purification with 35％ recovery was obtained in the case of 60％ aceton treatment and 10-fold purification with 5.6％ recovery was showed with 40％ aceton comparing to the crude extract Enzyme. (5) Crude enzyme precipitated with 0.4-0.6 saturated ammonium sulfate contained 13f6 of the original enzyme activity with 48-fold increase in specific activity and enzyme has been purified 25 fold with a yield 19％ by 0.6-5.8 saturation. (6) Hesperidinase formation was noticeably increased by addition of small amount of orange-peel extraction on the wheat bran medium.

• Microbiology and Biotechnology Letters
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• v.6 no.1
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• pp.41-46
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• 1978

Piscicidal substance produced by Streptomyces sp. isolated from soil was toxic against various kinds of fish. After extraction with CH$Cl_3$ from the culture medium, the substance was purified by avicel column chromatography. In order to test toxicity, various kinds of fish were subjected to the acqueous solution of 100 us of the substance per liter of water. Generally, the substance was toxic to most fish, but Macropodus chinenes and Misgurnus mizolepis are resistant to the substance than Gobius similis and Pseudorasbora parva. The substance was stable at pH range, 3.0 to 7.0, but labile at alkaline pH, and to heat as well. Succinic dehydrogenase on most of tissue cell of Cyprinus carpio was inhibited by this substance strongly, but spinal cord was not inhibited. By addition of Cu and Pb salts to the culture medium, piscicidal substance producibility was activated.