• Title/Summary/Keyword: Differential pulse voltammetry

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Chemical Properties of Cu( II ) Compound Containing Endocrine Disrupter, Bis-Phenol A

  • Park, Chil-Nam
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_3
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    • pp.121-126
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    • 2001
  • The techniques of pulse and cyclic voltammetry were applied to the determination of (E$_{1}$2)$_2$-(E$_{1}$2)$_1$ for two-step electrochemical charge transfers. In addition, a simple amplitude was derived far the dependence of the differential pulse response on (E$_{l}$ 2/)$_1$ and (E$_{1}$2/)$_2$. and the use of peak to peak separation in cyclic voltammetry and differential pulse methods was evaluated. A comparison of the comproportionation constants(Ke) from differential pulse and cyclic voltammetry methods exhibited a good agreement within 5%.

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Determination of Ag(Ⅰ) Ion at a Modified Carbon Paste Electrode Containing N,N'-Diphenyl Oxamide

  • Won, Mi-Sook;Yeom, Jeong-Sik;Yoon, Jang-Hee;Jeong, Euh-Duck;Shim, Yoon-Bo
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.948-952
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    • 2003
  • New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N'-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × $10^{-7}$ - 5.0 × $10^{-9}$ M at the deposition time of 10 min, with the detection limit was 7.0 × $10^{-10}$ M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × $10^{-10}$ M for silver and the relative standard deviation was ± 3.2% at a 5.0 × $10^{-8}$ M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.

Determination of Germanium(IV) by Differential Pulse Anodic Stripping Voltammetry(I) (Differential Pulse Anodic Stripping Voltammetry법에 의한 게르마늄 분석에 관한 연구(제1보))

  • 문동철
    • YAKHAK HOEJI
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    • v.27 no.1
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    • pp.1-10
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    • 1983
  • Voltammetric deposition and differential pulse anodic stripping (DPASV) of Ge(IV)at a gold electrode was investigated. Germanium (IV) exhibits two stripping peaks by DPASV in sodium borate solution, the first peak at about -1.1v. vs SCE and the second one, in the range of -0.6 to -0.2v. vs SCE. Factors affecting the sensitivity and precision included the nature of working electrode, supporting electrolytes, deposition potential, deposition time, pH, pulse height, voltage scan rate. The relative standard deviation of the measurements of the peak currents, for 100ng/ml Ge(IV), was less than ${\pm}3%$. The detection limit of Ge(IV) was 0.01ng/ml. Percent recovery in the extraction procedure of Ge(IV) from matrices by benzene in c-HCl, followed by back extraction with saturated borax solution, ranged from 96 to 104%.

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A Study on the Environmental Hormone

  • Chil Nam, Choi;Eun Jung, Na
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2001.05a
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    • pp.193-194
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    • 2001
  • To determine for the hybridization, we have investigated by UV spectroscopic method. This complex behavior as nonelectrolytes in polar aprotic solution with molar conductivities. The technoques of pulse and cyclic voltammetry have been applied to the determination of $(E_{1/2})_{2}$-$(E_{1/2})_{1}$ for two-step electrochemical charge transfers. A simple amplitude has been derived for the dependence of the differential-pulse response on $(E_{1/2})_{1}$ and $(E_{1/2})_{2}$. The use of the peak-to-peak separation in cyclic voltammetry has also been evaluated. Comparison with a differential pulse and cyclic voltammetry methods shows agreement of comproportionation constant$(K_{c})$ within 50%.

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Electrooxidation of DL-norvaline at Glassy Carbon Electrode: Approaching the Modified Electrode for Voltammetric Studies of Hydroquinone and Catechol

  • Kamel, Mahmoud M.
    • Journal of Electrochemical Science and Technology
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    • v.5 no.1
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    • pp.23-31
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    • 2014
  • The DL-norvaline was electrochemically oxidized and deposited on the glassy carbon electrode surface using cyclic voltammetry (CV). The modified electrode was examined for electrochemical oxidation of hydroquinone (HQ) and catechol (CC). It exhibited good electrocatalytic ability towards their oxidation and simultaneous determination in a binary mixture using differential pulse voltammetry (DPV). The peak currents were linear to the concentration of HQ and CC, in the range from $5{\mu}M$ to $100{\mu}M$, and $4{\mu}M$ to $140{\mu}M$, respectively. The determination limits(S/N = 3) for HQ and CC were $1{\mu}M$ and $0.8{\mu}M$, respectively. The obtained modified electrode was applied to simultaneous detection of HQ and CC in water sample.

Determination of Derivatives of Phenol with a Modified Electrode Containing β-Cyclodextrin

  • 김신희;원미숙;심윤보
    • Bulletin of the Korean Chemical Society
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    • v.17 no.4
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    • pp.342-347
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    • 1996
  • Voltammetric determination of phenol derivatives, such as phenol, o-, m-, and p-cresols was studied with a β-Cyclodextrin (β-CD) modified-carbon paste electrode composing of the graphite powder and Nujol oil. Phenol derivatives were chemically deposited via the complex formation with β-CD by immersing the CME into a sample solution. The resulting surfaces were characterized with cyclic and differential pulse voltammetry. Treating the CME with 1 M nitric acid for five sec after a measurement could regenerate the electrode surface. Linear sweep and differential pulse voltammograms were recorded for the above system to optimize the experimental parameters for analysing the phenol derivatives. In this case, the detection limit for phenols was 5.0×10-7M for 25 min of the deposition time with differential pulse voltammetry. The relative standard deviation was ±5.2% of 3.0×10-6M (four repetitions). The interference effect of the following organic compounds was also investigated; Bezoic acid, hippuric acid, o-, m-, and p-methylhippuric acid. Adding the organic compounds into the sample solution reduces the peak current of the phenols to about 25%.

Determination of Lead(II) at Nation-Coated Glassy Carbon Electrodes Modified by Tetren-Glycerol (Nafion-Tetren-Glycerol이 수식된 유리탄소전극에서 납(II) 이온의 정량)

  • 반옥기;박은희;정근호
    • Journal of Environmental Health Sciences
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    • v.29 no.2
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    • pp.62-68
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    • 2003
  • Differential pulse voltammetry (DPV) using nafion-coated glassy carbon electrodes modified with Tetren(tetraethylene pentamine)-glycerol showed sensitivity for determining lead (II) at low concentration. The Lead (II) was accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface was characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry. Various experimental parameters, such as the composition of modifier, preconcentration time, pH of electrolyte (0.1 M acetate buffer), and parameters of differential pulse voltammetry, were optimized. The initial potential was applied for 50 s, the electrode was scanned from -0.9 to -0.3 V, and the anodic peak current was measured at -0.604 V $\pm$ 0.015 V (vs. Ag/AgCl). The calibration plot was obtained in the range 1.0$\times$10$^{-8}$ M~l.0$\times$10$^{-6}$ M with pH 4.5 buffer solution. The detection limit (3$\sigma$) it as low as 5.0$\times$ 10$^{-9}$ M. This method is applied to the determination of lead(II) in a certified reference material and the result agrees satisfactorily with the certified value.

Determination of Cyanide Ion in the Presence of Sulfide Ion by Differential Pulse Cathodic Stripping Voltammetry (시차펄스 음극벗김 전압전류법에 의한 황화이온의 존재하에서 시안화이온의 정량)

  • Park, Se Yeon;Kwon, Young Soon
    • Analytical Science and Technology
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    • v.6 no.1
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    • pp.47-55
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    • 1993
  • The quantitative determination of trace cyanide ion in the presence of sulfide ion has been studied by addition of cupric ion using differential pulse Cathodic Stripping Voltammetry. The detection limit of cyanide ion in the presence of $5.0*10^{-5}M$ sulfide ion and $1.0*10^{-3}M$ cupric ion was $2.0*10^{-7}M$ in KCI-Phosphate buffer(pH=7.0) at accumulation potential -0.30V and accumulation time 3.0 min.

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Electrochemical Determination of GABA using a 3-D Nanoporous Gold Thin Film (3차원 구조의 다공성 금 박막을 이용한 GABA의 전기화학적 측정)

  • Pyo, Su-Hyun;Lee, Jin-Ho;Oh, Byeung-Keun
    • Applied Chemistry for Engineering
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    • v.22 no.5
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    • pp.575-578
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    • 2011
  • We fabricated a novel simple and rapid method of three dimensional nanoporous gold thin film (NPGF) onto a Au substrate using electrochemical deposition method. The NPGF-modified electrode analysis by scanning electron microscope and reveals the formation of nanopores, approximately 30~50 nm in diameter. differential pulse voltammetry was measured for the determination of ${\gamma}$-aminobutiric acid in the concentration range of ($10{\sim}100{\mu}M$ using a NPGF. The high sensitivity feature of NPGF is expected to be applied for real sample biosensor applications.

An Empirical Study on the Application of Lead-Acid Batteries to ESSs and Performance Improvement Methods

  • Jung, Hyun-Chul;Heo, Hoon
    • Journal of Power Electronics
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    • v.15 no.5
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    • pp.1295-1304
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    • 2015
  • In this paper, an approach to extend the life of lead-acid batteries through the elimination of sulfation with "rest time" using the pulse current of a conventional DPV (Differential Pulse Voltammetry) method is discussed. A new rest time without "0" current in "saw-tooth" pattern pulses is proposed to overcome the "0" current (blackout period), which is a shortcoming of DPV. This will enable the proposed method to be used in the loaded state. In the proposed approach, ESSs (Energy Storage Systems) were discharged for 5 h twice per day for 6 months on weekdays. To observe the changes in the lifespan of the systems, for the same period, the changes in the impedances of lead-acid batteries which were being charged e without charging and discharging were measure and compared. This study is focused on determining the effectiveness of lead-acid batteries as ESSs.