• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.73-82
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• 2003

Various forest humic substances were collected at different climate regions with different forest types, and adsorption of heavy metals such as Cu(II), Zn(II), Cd(II) and Cr(III) were characteristically conducted to obtain optimal adsorption conditions and to evaluate the removal efficiency of heavy metals by each forest humic substance. The adsorption isotherms for Cu(II), Zn(II), Cd(II) and Cr(III) conformed to Langmuir's equation. In the stirred reactor, the removal efficiencies of Cu(II), Zn(II) and Cd(II) by forest humic substances were more than 90% but that of Cr(III) was less than 60%. The adsorption capacities of heavy metals in the stirred reactor were considerably varied depending on the type of forest humic substances. Among humic substances, the one from deciduous forest at subtropical region showed the highest removal efficiency for Cu(II). There was no significant difference in removal efficiency by each heavy metal depending on reaction temperature ranged from 20 to 50oC except for Cr(III), and the adsorptions of Cu(II), Zn(II) and Cd(II) were occurred rapidly in the incipient stage within 10 min, while Cr(III) needed more reaction time to be adsorbed. The stirred and packed bed column reactors showed similar adsorption characteristics of heavy metals by humic substances, but the removal efficiency was considerably higher in the packed bed column reactor than in the stirred reactor. Therefore, in actual operation process, a continuous packed bed column reactor was more economical.

• 대한화학회지
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• 제12권2호
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• pp.47-50
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• 1968

Dowex $1{\times}4$ 陰이온 交煥樹指를 二段階(높이:下段 22cm, 上段 3cm, 直經 1.5cm)로 充塡하여 비스머스 金屬中에 들어있는 不純物인 Pb(II), Ag(I), Cu(II)를 7.5M 鹽酸으로, 그리고 Zn(II), Fe(III)를 0.5M 鹽酸으로 分離하고 上段에 남아있는 Te(IV)은 2M NaOH 용액으로 容出하고 아직도 上段에 남아있는 Au(III)는 樹脂를 태워서 分離하였다. 또 한가지 方法은 같은 樹脂를 10cm 높이로 一段階의 管에 充塡하여 0.5M 鹽酸으로 Pb(II), Ag(I), Cu(II), Fe(III), Zn(II)를 함께 容出하여 비스머스 中에서 分離하였다. 分離된 모든 不純物은 比色法으로 定量하였다.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.502-506
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• 2012

In order to find the structural characteristics of the thin films of group II-VI semiconductor compounds compared with those of powder materials, films were made of 4 powders of ZnS, CdS, CdSe, and CdTe(Aldrich), each with 99.99 % purity. For the ZnS/CdS multi-layers, the ZnS layer was coated over the CdS layer on an $AlO_x$ membrane, which served as a protective layer within a vacuum at the average speed of 1 ${\AA}$/sec. After studying the structures of the group II-VI semiconductor thin films by using X-ray spectroscopy, we found that the ZnS, ZnS/CdS, CdS, and CdSe films were hexagonal and exhibited some degree of preferred orientation. Also, the particles of the thin films of II-VI semiconductor compounds proved to be more homogeneous in size compared to those of the powder materials. These results were further verified through scanning electron microscopy(SEM), EDX analysis, and powder and thin film X-ray diffraction.

• 대한화학회지
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• 제35권5호
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• pp.512-519
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• 1991

유기용매$(CH_2Cl_2,\;C_6H_6,\;CH_3NO_2,\;(CH_3)_2CO,\;CHCl_3,\;DMF,\;DMSO)$에서 Zn(II)-, Cu(II)- 및 Ni(II)-tetrakis(o-chlorophenyl)porphyrin(o-ClTPP)과 Zn(II)-, Cu(II)- 및 Ni(II)-tetraphenylporphyrin(TPP) 착물과 질소원자를 포함한 염기성 리간드(pyridine, imidazole, 1-methylimidazole 및 2,6-lutidine)간의 결합 반응성을 이온강도 0.01M에서 연구하였다. metalloporphyrin과 염기성 리간드간의 평형상수는 온도범위 15 ~ 35${\circ}C$에서 분광광도법을 이용하여 결정하였으며, 이 때 M(II)-TPP에서 관찰된 평형상수는 입체적 장애가 더 큰 M(II)-(o-Cl)TPP에서 보다 큰 값을 나타내었다. M(II)-TPP에서 logK값은 염기성 리간드의 pKa값이 커질수록 증가하였지만 입체적장애를 받는 M(II)-(o-Cl)TPP에서 logK는 리간드의 $pK_a$값에 비례하지 않았다. 열역학적 파라미터 분석결과 M(o-Cl)TPP의 안정도는 거의 반응엔트로피에 의존하였으나, M(II)-TPPL의 안정도는 반응엔탈피와 반응엔트로피에 거의 비슷한 영향을 나타내었다. metalloporphyrin에 대한 용매의 배위능을 DMF, DMSO, $CHCl_3,\;(CH_3)_2CO$에서 측정하였고, 이들 결과로부터 평형상수에 대한 용매효과를 논의하였다.

• 대한화학회지
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• 제12권4호
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• pp.139-141
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• 1968

液狀이온交換體 Amberite LAI을 chloroform에 10%로 묽혀서 鹽酸算性에서 Bi(III), As(III), Sb(III), Zn(II) 및 Fe(III)의 推出率을 試驗한 結果, Zn(II)는 2M에서 98%. As(III)는 7~14M에서 Sb(III)는 2~4M에서 , Fe(III)는 6~10M에서 蒼鉛과 定量的으로 分離되었다. 그리고 chloroform을 溶媒로 썼을 때는 xylene이나 hexane을 溶媒로 썼을때보다 더 急傾斜를 이루는 推出率曲線을 나타냈다. 各各의 不純物을 分離後 Zn(II)는 dithizone. As(III)는 Gutzeit method, Sb(III)는 brilliant green, Fe(III)는 thiocyanate에 依한 比色方法으로 定量하였다.

• 대한화학회지
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• 제57권6호
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• pp.712-720
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• 2013

Microwave assisted syntheses of Zn(II), Cd(II) and Hg(II) complexes with 3-aminopyridine (3AP) and nitrite ($NO_2{^-}$) ions have been reported. The metal complexes were characterized by elemental analyses, molar conductance, IR, Far-IR, electronic, NMR ($^1H$, $^{13}C$), thermal and electron impact mass spectral studies. The spectroscopic studies reveal the composition, the nature of nitrite ligand in the complexes, electronic transitions, chemical environments of C and H atoms thermal degradation of the complexes. On the basis of characterization data, distorted tetrahedral geometry is suggested for Zn(II), Cd(II) and Hg(II) complexes. The organic ligand (3AP) and their metal complexes were screened against gram negative pathogenic bacteria and fungi in vitro. The results are compared with our previous report J. Korean Chem. Soc. 2013, 57, 341 on 4-aminopyridine and nitrite ion complexes of the same metal ions.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.8-12
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• 2007

All accessions of Rehmannia glutinosa show the unique characteristic of intrinsic tolerance to paraquat. The higher level of endogenous superoxide dismutase(SOD) activity and its increase upon paraquat treatment indicated the involvement of SOD in the tolerance mechanism to paraquat in R. glutinosa. In this study, we examined the isoform-specific response of SOD to oxidative stresses and hormones. Six SOD isoforms were found in the leaf, and they were identified as two MnSODs(named MnSOD I and MnSOD II, in order of increasing mobility), one FeSOD and three Cu/ZnSODs(named Cu/ZnSOD I, Cu/ZnSOD II, and Cu/ZnSOD III, in order of increasing mobility). MnSOD I, MnSOD II, FeSOD, Cu/ZnSOD I, Cu/ZnSOD II, and Cu/ZnSOD III, contributed to 4, 11, 7, 15, 30, and 32% of the total SOD activity, respectively. Total SOD activity levels in the leaf were increased by 4, 24, and 21% by paraquat, salicylic acid(SA), and yeast extract(YE), respectively, but little by ethephon. Six SOD isoforms responded differentially to these stresses and hormones. The activities of all the isoforms were increased by YE and SA except that of MnSOD I which was decreased by SA. The activities of MnSOD I, FeSOD, and CuZnSOD I were increased by paraquat. These results suggest that amelioration of oxidative stresses by SOD is fine-tuned by the differential expression of isoforms in R. glutinosa.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1477-1483
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• 2004

We present the tandem mass spectrometry applications carried out to elucidate the coordination structure of Zn(II) bound lysine ternary complexes, $(Zn+Lys+Lys-H)^+$, which is a good model system to represent a simple (metallo)enzyme-substrate complex (ES). In particular, experimental efforts were focused on revealing the involvement of a lysine side chain ${\varepsilon}$-amino group in the coordination of $Zn^{2+}$ divalent ions. MS/MS fragmentation pattern showed that all the oxygen species within a complex fell off in the form of $H_2O$ in contrast to those of other ternary complexes containing amino acids with simple side chains (4-coordinate geometries, Figure 1a), suggesting that the lysine complexes have different coordination structures from the others. The participation of a lysine basic side chain in the coordination of Zn(II) was experimentally evidenced in MS/MS for $N{\varepsilon}$-Acetyl-L-Lys Zn(II) complexes with acetyl protection groups as well as in MS/MS for the ternary complexes with one $NH_3$ loss, $(Zn+Lys+Lys-NH_3-H)^+$. Detailed structures were predicted using ab initio calculations on $(Zn+Lys+Lys-H)^+$ isomers with 4-, 5-, and 6-coordinate structures. A zwitterionic 4-coordinate complex (Figure 7d) and a 5-coordinate structure with distorted bipyramidal geometry (Figure 7b) are found to be most plausible in terms of energy stability and compatibility with the experimental observations, respectively.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3743-3748
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• 2013

A tetradentate ligand of 2-phenyl-4,6-di(pyridin-2-yl)pyrimidine (L) has been synthesized and its complexes with $ZnI_2$ and CuI have been obtained by hydrothermal method. single crystal X-ray diffraction analysis indicates that ligand L coordinates with Zn(II) ions to form a simple four-coordinate di-nuclear complex, while the complexation of L with Cu(I) constructs a one-dimensional chain polymer. The existence of $I^-$ ion hampers the L to assemble grid-type complexes with Zn(II) and Cu(I). Fluorescence spectra show that the L emits blue fluorescence while its Cu(I) polymer decrease the fluorescence intensity and Zn(II) complex quenches the fluorescence.

• Bulletin of the Korean Chemical Society
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• 제17권1호
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• pp.80-83
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• 1996