• Title/Summary/Keyword: 오스뮴

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Ultrastructural Study of Drosophila Ocellar Visual System by Osmium Impregnation (오스뮴침착법에 의한 초파리 단안시각계의 미세구조)

  • Yoon, Chun-Sik
    • Applied Microscopy
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    • v.29 no.4
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    • pp.451-457
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    • 1999
  • Ultrastructure of adult Drosophila ocellus was compared with conventional electron microscopic method and osmium impregnation. When osmium impregnation was applied, some organelles of cells were strongly stained. Especially, subrhabdomeric cisternae (SRC) were strongly stained and showed network-iike structure as in compound eye. Other organelles including SSC, ER, nuclear envelope, pigment granules and mitochondria were also strongly stained. These organelles are known as a general calcium ion reservoir. In conclusion, the strong effect of light and shade by osmium impregnation was regarded as a result of strong binding between calcium ion and osmium tetroxide. Thus, we agree to the opinion that osmium impregnation is very useful methods to the comparative morphology of cell organelles.

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Electrochemical Detection of Uric Acid using Three Osmium Hydrogels (세개의 오스뮴 고분자를 이용한 요산의 전기화학적 측정방법)

  • Jeon, Won-Yong;Choi, Young-Bong
    • Journal of the Korean Electrochemical Society
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    • v.19 no.2
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    • pp.29-38
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    • 2016
  • Screen printed carbon electrodes (SPCEs) with immobilized osmium-based hydrogel redox polymer, uricase and PEGDGE can be used to apply uric acid electrochemical detecting. The osmium redox complexes were synthesized by the coordinating pyridine group having different functional group at 4-position with osmium compounds. The synthesized poly-osmium hydrogel complexes are described as PAA-PVI-$[Os(dCl-bpy)_2Cl]^{+/2+}$, PAA-PVI-$[Os(dme-bpy)_2Cl]^{+/2+}$, PAA-PVI-$[Os(dmo-bpy)_2Cl]^{+/2+}$. The different concentrations of uric acid were measured by cyclic voltammetry technique using enzyme-immobilized SPCEs. The prepared SPCEs using PAA-PVI-$[Os(dme-bpy)_2Cl]^{+/2+}$ showed no interference from common physiologic interferents such as ascorbic acid (AA) or glucose. The resulting electrical currents at 0.33 V vs. Ag/AgCl displayed a good linear response with uric acid concentrations from 1.0 to 5.0 mM. Therefore, this approach allowed the development of a simple, point of care in the medical field, disposable electrochemical uric acid biosensor.

Stripping Voltammetric Determination of Osmium (벗김 전압전류법에 의한 오스뮴 정량)

  • Kwon, Young-Soon;Kim, So-Jin;Czae, Myung-Zoon
    • Analytical Science and Technology
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    • v.10 no.2
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    • pp.114-118
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    • 1997
  • A stripping voltammetric scheme for the determination of osmium, based on the adsorptive accumulation of osmium in the presence of hydroxylamine, was described. Cyclic voltammetry was used to characterize the redox and interfacial processes. Optimal experimental conditions were found to be a stirred 0.05M hydroxylamine hydrochloride solution(pH 1.8), accumulation at -0.65V for 60s, and a differential pulse mode with a scan rate of 10mV/s. The detection limit was $6.3{\times}10^{-8}M$(12ppb) with the optimal condition.

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Technology for the Recovery of Os and Ru from Primary/Secondary Resources (1차(次)/2차(次) 자원(資源)으로부터 Os과 Ru 회수기술(回收技術))

  • Sun, Pan-Pan;Lee, Man-Seung
    • Resources Recycling
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    • v.21 no.6
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    • pp.3-11
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    • 2012
  • Some methods used for the recovery of osmium and ruthenium from primary/secondary sources are reviewed. Both Ru and Os could form volatile oxides which enable their separation from the other PGMs by distillation as a traditional method. In hydrochloric acid solution, they also form chloro-complexes with different valence states. Amines or amine based mixture have been used to extract Ru. Solvating extractants are employed to separate Ru and Os. The detailed extraction and stripping conditions of several solvent extraction processes have been reviewed. As an alternative to solvent extraction, solid-liquid method can be applied to recover trace amount of these metals.

Electrochemical behavior and Application of Osmium-Cupferron Complex (오스뮴-쿠페론의 전기화학적 행동 및 응용)

  • Kwon, Young-Soon;Chong, Mee-Young
    • Analytical Science and Technology
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    • v.16 no.3
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    • pp.198-205
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    • 2003
  • The ammonium salt of nitrosophenylhydroxylamine, called cupferron, has been used not only as the ligand but also as an oxidizing agent for adsorptive catalytic stripping voltammetry (AdCtSV). Cyclic voltammetry was used for elucidating the electrochemical behavior of Os-cupferron complex in 1 mM phosphate buffer. The optimal conditions for osmium analysis were found to be 1 mM phosphate buffer solution (pH 6.0) containing 0.1 mM cupferron at scan rate of 100 mV/s. By using the plot of reduction peak currents of linear scan voltammograms vs. osmium concentration, the detection limit was $1.0{\times}10^{-7}M$.

Electrochemical Immobilization of Osmium Complex onto the Carbon Nano-Tube Electrodes and its Application for Glucose sensor (전기화학적인 방법을 이용한 탄소나노튜브 전극상의 오스뮴 착물의 고정화 및 혈당센서에 관한 응용)

  • Choi, Young-Bong;Jeon, Won-Yong;Kim, Hyug-Han
    • Journal of the Korean Electrochemical Society
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    • v.13 no.1
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    • pp.50-56
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    • 2010
  • The multi-wall carbon nano-tube composite mixed with carbon paste electrode presented more sensitive and selective amperometric signals in the oxidation of glucose than general screen-printed carbon electrodes(SPCEs). Redox mediators to transport electrodes from enzyme to electrodes are very important part in the biosensor. A novel osmium redox complex was synthesized by the coordinating pyridine group containing primary amines which were electrochemically immobilized onto the MWCNT-SPCEs surface. Electrochemical studies of osmium complexes were investigated by cyclic voltammetry, chronoamperometry. The surface coverage of osmium complexes on the modified carbon nano-tube electrodes were significantly increased at 100 time (${\tau}_0=2.0\;{\times}\;10^{-9}\;mole/cm^2$) compared to that of the unmodified carbon electrodes. It's practical application of the glucose biosensor demonstrated that it shows good linear response to the glucose concentration in the range of 0-10 mM.

Synthesis of Osmium Redox Complex and Its Application for Biosensor Using an Electrochemical Method (오스뮴 착물 합성과 전기화학적인 방법을 이용한 바이오센서에 관한 연구)

  • Choi, Young-Bong;Kim, Hyug-Han
    • Journal of the Korean Electrochemical Society
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    • v.10 no.2
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    • pp.150-154
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    • 2007
  • Redox complexes to transport electrodes from biomaterial to electrodes are very important part in commercial biosensor industry. A novel osmium redox complex was synthesized by the coordinating pyridine group with osmium metal. A novel osmium complex is described as $[Os(dme-bpy)_2(ap-im)Cl]^{+/2+}$. We have been studied the electrochemical characteristics of this osmium complex with electrochemical techniques such as cyclic voltammetry and chronoamperommetry. In order to immobilize osmium redox complexes on the electrode, we deposited gold nano-particles on screen printed carbon electrode(SPE). The electrical signal converts the osmium redox films into an electrocatalyst for glucose oxidation. The catalytic currents were monitored that the catalytic currents were linearly increased from 1 mM to 5 mM concentrations of glucose.