• 대한환경공학회지
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• 제28권5호
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• pp.527-534
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• 2006

본 연구의 목적은 폐수 중의 음이온성 오염물질을 효율적으로 제거하기 위한 필터형의 고분자 흡착제를 개발하는데 있다. 음이온 교환기능기를 갖는 고분자 흡착제를 합성하기 위하여 DETA를 아민원으로 하는 화학적 개질반응을 이용하여 PP-g-AA 부직포의 카르복시기를 아민기로 변환시켰다. FT-IR분석결과는 그라프트된 아크릴산이 DETA와 반응하여 아미드화됨에 따라 PP-g-AA에 아민그룹이 도입되었음을 시사하였다. PP-g-AA의 아민화율은 반응온도가 높을수록, 반응시간이 길수록 증가하였으며, PP-g-AA 부직포를 용매를 이용하여 먼저 팽윤시키거나 금속염화물 촉매를 첨가한 다음 아민화 반응을 실시하였을 때 더욱 증가하였다. 팽윤용매별 아민화율은 $NH_4OH>HCl{\geq}MeOH>H_2O$, 금속염화물 촉매별 아민화율은 $AlCl_3>FeCl_3{\geq}SnCl_2{\gg}ZnCl_2{\geq}FeCl_2$순으로 높게 나타났다. 다만 촉매의 첨가는 DETA의 재사용을 제한하기 때문에 제조비용과 폐기물 관리면에서 그 유용성이 낮았다. PP-g-AA-Am 부직포의 음이온 교환능은 아민화율이 증가할수록 증가하였으나 대략 $50{\sim}60%$의 아민화율에서 최대가 되었으며, 상용의 음이온교환수지의 교환능에 비해 높았다.

• 한국식품과학회지
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• 제15권2호
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• pp.133-134
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• 1983

Some metallic ions such as copper, manganese, iron, zinc and cadmium in ginseng extract, originated from white ginseng, were determined by atomic absorption spectrophotometry. The extracts were prepared with water, 35% ethanol, 50% ethanol or 75% ethanol solution followed by filtration or centrifugation. Greater amounts of metallic ions were found in the solution filtrated by filter paper (Toyo No. 5A) or by filter cloth than in that of centrifugation. The residual amount of metallic ions in the extract decreased with increasing concentration of ethanol. The percentages of each metallic ion in ginseng extracts on the basis of original amount of metallic ions were as follows: Cu, 10.4-31.9%, Fe,5.1-19.0%, Mn,3.0-12.2% Zn,7.4-12.0%, Cd,5.9-11.8%.

• 자원환경지질
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• 제25권1호
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• pp.27-39
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• 1992

Several pyrophyllite deposits occur around the Milyang area where Cretaceous andesitic rocks and spatially related granitic rocks are widely distributed. Pyrophyllite ores consist mainly of pyrophyllite, and quartz with small amount of sericite, pyrite, dumortierite, and diaspore. The andesitic rocks and spatially related granitic rocks in this area suggest that they could be formed from the same series of a calc-alkaline magma series. The contents of $SiO_2$, $Al_2O_3$, LOI(loss on ignition) are enriched, and $K_2O$, $Na_2O$, CaO, MgO, $Fe_2O_3$ are depleted in altered andesitic rocks and ores. Enrichment of As, Cr, Sr, V, Sb and depletion of Ba, Cs, Ni, Rb, U, Y, Co, Sc, Zn are characteristic during mineralization. The pyrophyllite ores can be discriminated from the altered-and unaltered wall-rocks by an increasing of $(La/Lu)_{cn}$ from 4.18~22.13 to 8.98~55.05. In R-mode cluster analysis, Yb-Lu-Y, La-Ce-Hf-Th-U-Zr, $TiO_2-V-Al_2O_3$, Sm-Eu, $CaO-Na_2O-MnO$, Cu-Zn-Ag, $K_2O-Rb$ are closely correlated. In the discriminant analysis of multi-element data, $P_2O_5$, As, Cr and $Fe_2O_3$, Sr are helpful to identify the ores from the unaltered-and altered wall-rocks. In the factor analysis, the factors of alteration of andesitic rocks and ore mineralization were extracted. In the change of ions per unit volume, $SiO_2$, $Al^{3+}$ and LOI are enriched and $Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Mn^{2+}$ and $Fe^{3+}$ are depleted during the alteration processes. The Milyang and the Sungjin pyrophyllite deposits could be mineralized by hydrothermal alteration in a geochemical condition of low activity ratio of alkaline ions to hydrogen ion with reference to spatially related granitic rocks.

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.346-350
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• 2002

A glassy carbon electrode (GCE) modified with 2,2':6':2”-terpyridine (2,2':6':2”-TPR) using a spin coating method was applied for the highly selective and sensitive analysis of a trace amount of $Hg_2^{2+}$ ions. Various experimental parameters, which influenced the response of the 2,2':6':2”-TPR modified electrode to $Hg_2^{2+}$ ions, were optimized. The linear sweep and differential pulse voltammograms for the 2,2':6':2”-TPR modified electrode deposited with Hg show a well-defined anodic peak at +0.65 V (vs. Ag|AgCl). After a 25 min preconcentration time in an $Hg_2^{2+}$ ion solution (0.1 M acetate buffer, pH 5.0), differential pulse voltammetry(DPV) with 2,2':6':2”-TPR modified electrode shows a linear response between $1.0\;{\times}\;10^{-6}M\;and\;2.0\;{\times}\;10^{-7}M$. The least-square treatment of these data produce an equation of I[${\mu}A$] = 0.031 + 0.005C with r = 0.980(n = 5). The detection limit of this electrode with linear sweep voltammetry and differential pulse anodic voltammetry were $2.0\;{\times}\;10^{-6}M\;and\;8.0\;{\times}\;10^{-8}M$, respectively. The presence of Pb, Fe, Cd, Ti, Ni, Co, Mg, Al, Mn, and Zn did not interfere in the analysis of the $Hg_2^{2+}$ ion. The 2,2':6':2”-TPR modified GCE has been successfully applied in determination trace amounts of Hg in a human urine sample.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.122-126
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• 2011

A new phosphorescent cyclometalated heteroleptic iridium (III) complex with an ancillary ligand of 4-azacrownpicolinate was prepared and its metal ion selective phosphorescent chemosensing behavior was investigated. The new iridium (III) complex exhibits notable phosphorescence quenching for Hg2+ in aqueous 50% acetonitrile solution with respect to the selective phosphorescent detection of various metal ions including $Li^+,Na^+,K^+,Cs^+,Mg^{2+},Ca^{2+},Ba^{2+},Fe^{2+},Ni^{2+},Cu^{2+},Zn^{2+},Ag^+,Pb^{2+},Cd^{2+},Cr^{2+},Cr^{3+}$ and $Hg^{2+}$. The phosphorescence quenching for $Hg^{2+}$ increased linearly with increasing concentration of $Hg^{2+}$ in the range of $10{\mu}M-700{\mu}M$ even in the presence of other metal ions, except for $Cu^{2+}$. Consequently, the new iridium (III) complex has the potential to be utilized for the determination of parts per million levels of $Hg^{2+}$ in aqueous acetonitrile media.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3212-3216
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• 2010

A new rhodamine-based sensor 1 was designed and synthesized by incorporating rhodamine B and benzimidazole moieties. Sensor 1 exhibits high selectivity and sensitivity to $Cu^{2+}$ in $CH_3CN$-water solution (HEPES buffer, pH = 7.0) with an obvious color change from colorless to pink. Other metal ions such as $Hg^{2+}$, $Ag^+$, $Pb^{2+}$, $Sr^{2+}$, $Ba^{2+}$, $Cd^{2+}$, $Ni^{2+}$, $Co^{2+}$, $Fe^{2+}$, $Mn^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Ce^{3+}$, $Mg^{2+}$, $K^+$ and $Na^+$ had no such color change and have no significant influence on $Cu^{2+}$ recognition process. The interaction of $Cu^{2+}$ and sensor 1 was proven to adopt a 1:1 binding stoichiometry and the recognition process is reversible.

• Applied Biological Chemistry
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• 제31권4호
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• pp.331-338
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• 1988

칡뿌리로 부터 칡뿌리 acetone분말을 제조하고 polyphenol oxidase를 추출, 정제하여 정제효소의 효소학적 특성을 검토하였다. 조효소는 DEAE-Cellulose, DEAE-Sephadex A-50, Sephadex G-100 column chromatography에 의하여 정제되었으며, 정제효소의 비활성은 94배, 정제수율은 45.4%이었다. 정제효소는 catechol 및 pyrogallol에 대하여 감한 친화성을 나타내었으며, km 값은 catechel을 기질로 하였을 때 16.67mM이었다. 작용 최적 pH는 7.5, 최적온도는 $50^{\circ}C$에서 가장 잘 작용하였고 1mM L-ascorbic acid, sodium bisulfite, EDTA, KCN 및 $Fe^{3+}$ 이온에 의하여 심한 저해를 나타내었으며, $Zn^{2+}$ 이온을 약 1.7배 정도의 활성을 증가시켰다. 조효소액을 전기영동하여 catechol로 활성염색 하였을 때 5개 isoenzyme이 확인되었으며 그 중 분자량 35,000의 것이 가장 강한 활성을 나타내었다.

• BMB Reports
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• 제28권2호
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• pp.170-176
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• 1995

Rhodanese from mouse liver was purified to near homogeneity by ammonium sulfate precipitation, CM-Sephadex ion exchange, hydroxyapatite and Sephacryl S-200-HR gel filtration chromatographies with a purification of 776 folds. The molecular weight was determined by Sephadex G-150 gel filtration and found to be 34.8 KDa. SOS-PAGE showed molecular weight 34 KDa and two identical subunits splitting by aging for 3 weeks at $-70^{\circ}C$ the molecular weight of which was 17 KDa. The optimal pH of enzyme activity was 9.4 and the pI value of the enzyme was 6.6. Rhodanese showed the optimal reaction temperature of $25^{\circ}C$ and near linear increasing pattern until 10 min. incubation. $K_m$ values of rhodanese for KCN and $Na_{2}S_{2}O_{3}$ as substrates were 12.5 mM and 8.3 mM, respectively. Rhodanese activity was inhibited by more than 70% at a concentration of 100 ${\mu}M$ of $Ni^{2+}$, $Zn^{2+}$, $Cd^{2+}$, $Hg^{2+}$ and $Cu^{2+}$. Other metal ions, such as $Mn^{2+}$, $Mg^{2-}$, $Ca^{2+}$, and $Fe^{2+}$ showed no effect on rhodanese activity.

• 한국식품위생안전성학회지
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• 제26권1호
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• pp.76-81
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• 2011

The protease produced by a Bacillus pumilus CN8 strain was purified by DEAE-Cellulose-52 ion exchange. It has a molecular weight of approximately 96,920 Dalton. In the present study, this protease showed strong activity over a broad range of pH (6.5-9.5) and temperature from $40^{\circ}C$ to $60^{\circ}C$, and the protease performed the maximal activity at pH 7.3 at $42^{\circ}C$. The effect of metal ions on protease activity showed that $K^+$ could slightly increase the protease activity, and other ions such as $Zn^{2+}$, $Fe^{2+}$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$ had no significant activation or inhibition to the protease (P> 0.05), and the more important is that $Cu^{2+}$, $Mn^{2+}$, $Sn^{2+}$, $Cd^{2+}$ had a strong inhibitory effect on the protease activity.

• 산업기술연구
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• 제39권1호
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• pp.15-19
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• 2019

This work focused on characterization of the starch degradation activity from extremophile strain Deinococcus geothermalis. Glucoamylase gene from D. geothermalis was cloned and overexpressed by pET-21a vector using E. coli BL21 (DE3). In order to characterize starch degrading activity of recombinant glucoamylase, enzyme was purified using HisPur Ni-NTA column. The recombinant glucoamylase from D. geothermalis exhibited the optimum temperature as $45^{\circ}C$ for starch degradation activity. And highly acido-stable starch degrading activity was shown at pH 2. For further optimization of starch degrading activity with metal ion, various metal ions ($AgCl_2$, $HgCl_2$, $MnSO_4{\cdot}4H_2O$, $CoCl_2{\cdot}6H_2O$, $MgSO_4$, $ZnSO_4{\cdot}7H_2O$, $K_2SO_4$, $FeCl_2{\cdot}4H_2O$, NaCl, or $CuSO_4$) were added for enzyme reaction. As results, it was found that $FeCl_2{\cdot}4H_2O$ or $MnSO_4{\cdot}4H_2O$ addition resulted in 17% and 9% improved starch degrading activity, respectively. The recombinant glucoamylase from D. geothermalis might be used for simultaneous saccharification and fermentation (SSF) process at high acidic conditions.