• Title/Summary/Keyword: Square Wave Voltammetry

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Germanium(IV) Content in the Korean Angelica keiskei Koidz (국내산(國內産) 명일엽(明日葉)의 부위별 게르마늄 함량(含量))

  • Jeong, Seung-Il;Han, Wan-Soo
    • Korean Journal of Medicinal Crop Science
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    • v.7 no.1
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    • pp.11-15
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    • 1999
  • The uptake of germanium(Ge) by health foodstuffs was interesting because of a therapeutic effect of organic germanium. Germanium contents in different plant parts of the cultivated Korean Angelica keiskej Koidz in several growing districts were determined by square wave anodic stripping voltammetry. Experimental conditions in germanium determination from Angelica kejskej Koidz were as follows : deposition time; 20 sec, deposition potential; -0.9 volts vs Ag/AgCl, and frequency; 100 Hz in 0.1M\;HClO_4, supporting electrolyte solution at pH 2.43 containing $1.5\;{\times}\;10^5\;M$ pyrocatechol violet. Calibration curve showed a good lineality in the range of 0.4 ppb to 2.0 ppm and the detection limit was 0.08 ppb. There was a large difference in content according to growing districts ranging from 102 to 386ppm. Germanium content in leaf parts was much higher than that in stems.

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Integrated Microdisk Gold Electrode Modified with Metal-porphyrin and Metal-phthalocyanines for Nitric Oxide Determination in Biological Media

  • Kim, Il-Kwang;Bae, Hyun-Ok;Oh, Gi-Soo;Chung, Hun-Taeg;Kim, Young-Jin;Chun, Hyun-Ja
    • Bulletin of the Korean Chemical Society
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    • v.24 no.11
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    • pp.1579-1584
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    • 2003
  • An integrated gold microdisk electrode was constructed and modified with metal-porphyrin or metal-phthalocyanines for NO determination in biological media. Microanalysis of NO using square wave anodic stripping voltammetry in $1\;{\times}\;10^{-2}$ M $HClO_4$ was optimal when the accumulation potential was 0.1 V, frequency 100 Hz, and the scan rate was 200 mV/s. When the electrode was modified with metal-porphyrin or metal-phthalocyanines, the anodic peak currents of NO increased due to the catalytic oxidation of NO. In case of Fe(II)-phthalocyanine modified electrode, the peak currents remarkably increased and the sensitivity was high. The calibration curve had good linearity in the range from $3.6\;{\times}\;10^{-5}$ M to $7.2\;{\times}\;10^{-7}$ M, and the detection limit was $5.7\;{\times}\;10^{-7}$ M. For the structural stability and increased sensitivity, Fe(II)-phthalocyanine modified gold microdisk electrode coated with Nafion was applied to determination of NO released from cultured macrophase.

Real-time Voltammetric Assay of Cadmium Ions in Plant Tissue and Fish Brain Core

  • Ly, Suw-Young
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1613-1617
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    • 2006
  • Optimum analytical conditions for cyclic voltammetry (CV) and square wave (SW) stripping voltammetry were determined using mercury-mixed carbon nanotube paste electrode (PE). The results approached the microgram working ranges of SW: 10.0-80.0 $ugL^{-1}$ and CV: 100-700 $ugL^{-1}$ Cd (II); working conditions of 300-Hz frequency, 100 mV amplitude, 1.6 V accumulation potential, 400 sec accumulation time, and 40 mV increment potential. First, analysis was performed through direct assay of cadmium ions deep into the fishs brain core and plant tissue in real time with a preconcentration time of 400 sec. The relative standard deviation of 10.0 $mgL^{-1}$ Cd (II) observed was 0.064 (n = 12) at optimum conditions. The low detection limit (S/N) was set at 0.6 $ugL^{-1}$ ($5.33{\times}10^{-9}$ M). The methods can be used in direct analysis in vivo or in real-time monitoring of plant tissue.

Voltammetric Assay of Mercury Ion in Fish Kidneys

  • Ly, Suw-Young
    • Toxicological Research
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    • v.24 no.1
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    • pp.23-28
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    • 2008
  • Voltammetric analysis of mercury ions was developed using paste electrodes (PEs) with DNA and carbon nanotube mixed electrodes. The optimized analytical results of the cyclic voltammetry (CV) of the $1{\sim}14ng\;L^{-1}Hg(II)$ concentration and the square wave (SW) stripping voltammetry of the $1{\sim}12ng\;L^{-1}Hg(II)$ working range within an accumulation time of 400 seconds were obtained in 0.1 M $NH_4H_2PO_4$ electrolyte solutions of pH 4.0. For the relative standard deviations of the $1ng\;L^{-1}Hg(II)$, which were observed at 0.078% (n = 15) at the optimum conditions, the low detection limit (S/N) was pegged at $0.2ng\;L^{-1}(7.37{\times}10^{-13}M)$ for Hg(II). The results can be applied to assays in biological fish kidneys and wastewater samples.

Electrochemical Detection of Pesticide in Living Plant and Fish Brain Cell

  • Lee, Chang-Hyun;Ly, Suw-Young
    • Journal of Environmental Science International
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    • v.19 no.8
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    • pp.941-949
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    • 2010
  • The three electrode system was used to detect the pesticide fenitrothion ($C_9H_{12}NO_5PS$. MW=277.24) using cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The working electrode was mercury immobilized on a carbon nanotube paste electrode (Hg-CNTPE). At the optimized condition, the limit of detection (LoD) was 0.6 ppt ($2.16{\times}10^{-12}\;M$), and the relative standard deviation was 0.035% (n=15). And there is more sensitive in detecting fenitrothion than common type carbon nanotube paste electrode. When it was implanted into the brain of live fish (carp), the existence of fenitrothion was measured without any destruction or damage of tissue.

Voltammetric Studies of Cu-Adriblastina Complex and its Effect on ssDNA-Adriblastina Interaction at In Situ Mercury Film Electrode

  • D.Abd El Hady;M.Ibrahim Abdel Hamid;M.Mahmoud Sellem;N.Abo E Maali
    • Archives of Pharmacal Research
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    • v.27 no.11
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    • pp.1161-1167
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    • 2004
  • Adriblastina, a cancerostatic anthracycline antibiotic, causes considerable oxidative damage to DNA molecules. The interaction of this compound with DNA was investigated using Osteryoung square wave stripping voltammetry (OSWSV) and cyclic voltammetry (CV) at an in situ mercury film electrode. It was found that the equilibrium constant of the bonded oxidized form of the drug was 63 times bigger more important than that of the bonded reduced form. Copper forms 1 metal: 2 drug stoichiometry complex which is highly stable compared to ssDNA-drug interaction and consequently inhibited the drug biochemical damaging effects. Copper complex offered sub-nanogram determination of adriblastina in aqueous and urine media.

Assay of Dinitrotoluene on a Contaminated Soil Sample with an Anodic Stripping Peak Current

  • Ly, Suw-Young;Lee, Chang-Hyun;Jung, Young-Sam
    • Journal of Environmental Science International
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    • v.15 no.11
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    • pp.997-1002
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    • 2006
  • This report presents a voltammetric assay of dinitrotoluene using a DNA immobilized onto a carbon nanotube paste electrode (PE). The cyclic voltammetry (CV) and square wave (SW) stripping voltammetry parameters of the optimized conditions were obtained. An anodic peak current appeared at 0.3 V (versus Ag/AgCl) in a 0.1-M $NH_4H_2PO_4$ electrolyte solution. The detection limit was found to be $0.6ngL^{-1}$(S/N = 10), within a deposition time of 100 sec.

DEVELOPMENT OF ANODIC STRIPPING VOLTAMMETRY FOR THE DETERMINATION OF PALLADIUM IN HIGH LEVEL NUCLEAR WASTE

  • Bhardwaj, T.K.;Sharma, H.S.;Jain, P.C.;Aggarwal, S.K.
    • Nuclear Engineering and Technology
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    • v.44 no.8
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    • pp.939-944
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    • 2012
  • Deposition potential, deposition time, square wave frequency, rotation speed of the rotating disc electrode, and palladium concentration were studied on a Glassy Carbon Electrode (GCE) in 0.01M HCl for the determination of palladium in High Level Nuclear Waste (HLNW) by anodic stripping voltammetry. Experimental conditions were optimized for the determination of palladium at two different, $10^{-8}$ and $10^{-7}M$, levels. Error and standard deviation of this method were under 1% for all palladium standard solutions. The developed technique was successfully applied as a subsidiary method for the determination of palladium in simulated high level nuclear waste with very good precision and high accuracy (under 1 % error and standard deviation).

Diagnostic Calculation of Trace Calcium Ions in Food Using a DNA doped Sensor

  • Yang, Young-Kyun;Ly, Suw-Young
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.2
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    • pp.197-203
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    • 2013
  • The diagnostic assay of calcium ion was sought using a modified sensor with square-wave stripping voltammetry (SWSV) and cyclic voltammetry (CV). In this study, simple graphite pencil was used as working, reference, and auxiliary electrodes. By coating the working electrodes with DNA, their sensitivity was very much improved, and good results were yielded. Moreover, clean seawater was used as an electrolyte solution instead of acid and base electrolytes to lessen the expenses involved in the experiment. The analytical optimum conditions were also examined. These conditions were attained at the low detection limit of $0.6ugL^1$. After that, the results were applied to drinking water of milk contain.

Detection of Toxic Heavy Metal, Co(II) Trace via Voltammetry with Semiconductor Microelectrodes

  • Ly, Suw Young;Lee, Chang Hyun;Koo, Jae Mo
    • Toxicological Research
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    • v.33 no.2
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    • pp.135-140
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    • 2017
  • The cobalt (Co(II)) ion is a main component of alloys and considered to be carcinogenic, especially due to the carcinogenic and toxicological effects in the aquatic environment. The toxic trace of the Co(II) detection was conducted using the infrared photodiode electrode (IPDE) using a working electrode, via the cyclic and square-wave anodic stripping voltammetry. The results indicated a sensitive oxidation peak current of Co(II) on the IPDE. Under the optimal conditions, the common-type glassy carbon, the metal platinum, the carbon paste, and the carbon fiber microelectrode were compared with the IPDE in the electrolyte using the standard Co(II). The IPDE was found to be far superior to the others.