• Bulletin of the Korean Chemical Society
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• 제22권10호
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• pp.1141-1144
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• 2001

• 전기화학회지
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• 제17권4호
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• pp.216-221
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• 2014

전기 화학적으로 활성화된 glassy carbon 전극을 사용하여 Clenbuterol 의 정량측정을 위해 신속하고 민감한 전압-전류 법을 개발하였다. 시차 펄스 전압-전류 법(Differential pulse voltammetry)을 이용하여, Clenbuterol에 대해 $1{\times}10^{-7}M$에서 $2{\times}10^{-5}M$의 범위에서 선형적인 반응을 보였으며 검출한계는 $6{\times}10^{-9}M$ (S/N = 3)이었다. Clenbuterol 의 농도가 $1{\times}10^{-6}M$에서의 상대표준편차는 4.3%이었다. 다양한 양의Clenbuterol이 포함된 소변 샘플로부터 96%의 회수율을 나타냈다. (N = 3, $5{\times}10^{-7}M$에서 $1{\times}10^{-6}M$의 Clenbuterol)

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.200-205
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• 1990

Chemically modified electrodes(CMEs), based on 2-imino-1-cyclopentane-dithiocarboxylic acid (icdc) containing carbon paste, have been characterized using cyclic voltammetric techniques. Ag(I) was chemically deposited on the CMEs, and voltammograms were obtained with the electrode in a separate buffer solution. The CME surface can be regenerated with exposure to acid and reused for deposition. In 10 deposition/measurement/regenerate cycles, the linear response have been reproduced up to $1{\times}10^{-6}$ M in linear sweep voltammetry and 1${\times}$10-8 M in differential pulse voltammetry with relative standard deviation of 5.2% and 12.4%, respectiveiy. The sensitivity increased with deposition time and scanning rate, and detection limit was $1{\times}10^{-7}M\;and\;1{\times}10^{-9}M$ at 20 minutes deposition in the linear sweep voltammetry and differential pulse voltammetry, respectively. The presence of some metal ions does not influence the silver ion response. Satisfactory results were obtained for the analysis of the silver ion for a variety of reference materials without interference of Hg ion at the condition of pH = 5-6.

• 통합자연과학논문집
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• 제7권3호
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• pp.188-192
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• 2014

Determination of cobalt(III) ion with a perfluorinated sulfonated polymer-ethylenediamine (nafion-en) modified glassy carbon electrode is studied. It is based on the chemical reactivity of an immobilized layer, nafion-en, to yield complex $[Co(en)_3]^{3+}$. The reduction peak potential by differential pulse voltammetry (DPV) is observed at $-0.437{\pm}0.047$ V (vs. Ag/AgCl). The linear calibration curve is obtained in cobalt(III) ion concentration range $1.0{\times}10^{-8}{\sim}1.0{\times}10^{-3}M$ ($5.893{\times}10^{-12}{\sim}5.893{\times}10^{-5}g/mL$).

• 한국환경보건학회지
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• 제28권5호
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• pp.53-58
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• 2002

A method for the determination of lead(II) ion using a nafion-EDTA(ethylene diamine tetraacetic acid)-glycerol modified glassy carbon electrode was proposed. Lead(II) ion is accumulated at the electrode by complexation and electrostatic attraction with nafion-EDTA-glycerol and detected at -0.560$\pm$0.015V (vs. Ag/AgCl) by differential pulse voltammetry. For the determination of lead(II) ion, a standard calibration curve if obtained from 10$^{-9}$ M lead(II) ion to 10$^{-7}$ M, and the detection limit(3s) is as low as 5.0$\times$10$^{-10}$ M.

• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.38-42
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• 2008

The voltammetic behavior of Vitamin B6 (VB6) was studied at a glassy carbon electrode in phosphate buffers using cyclic, linear sweep and differential pulse voltammetry. The oxidation process was shown to be irreversible over the entire pH range studied (4.0-10.0) and was adsorption controlled. The adsorption amount of VB6 on the glassy carbon electrode was examined by chronocoulometry and the value of n, product of transfer coefficient and number of electrons transferred in the rate determining step, was determined from Tafel plot. VB6 was determined by differential pulse voltammetry and the peak current was found linearly with its concentration in the range of 3 10-7-2 10-4 mol L-1. The detection limit was 1 10-7 mol L-1. The procedure was successfully applied for the assay of VB6 in tablets.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1755-1762
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• 2013

A graphene-Zn/Al layered double hydroxide composite film was simultaneously prepared by electrochemical deposition on the surface of a glassy carbon electrode (G-LDH/GCE) from the mixture solution containing GO and nitrate salts of $Zn^{2+}$ and $Al^{3+}$. The modified electrode showed good electrochemical performances toward the simultaneous electrochemical detection of hydroquinone (HQ), catechol (CA) and resorcinol (RE) due to the unique properties of graphene (G) and LDH such as large active surface area, facile electronic transport and high electrocatalytic activity. The redox characteristics of G-LDH/GCE were investigated with cyclic voltammetry and differential pulse voltammetry. The well-separated oxidation peak potentials, corresponding to the oxidation of HQ, CA and RE, were observed at 0.126 V, 0.228 V and 0.620 V respectively. The amperometric response of the modified electrode exhibited that HQ can be detected without interference of CA and RE. Under the optimized conditions, the oxidation peak current of HQ is linear with the concentration of HQ from 6.0 ${\mu}M$ to 325.0 ${\mu}M$ with the detection limit of 0.077 ${\mu}M$ (S/N=3). The modified electrode was successfully applied to the direct determination of HQ in a local tap water, showing reliable recovery data.

• 대한화학회지
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• 제32권2호
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• pp.130-134
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• 1988

수은방울전극에서 바로 시안이온을 시차펄스음극벗김 전압전류 법으로 측정한 결과 검출한계를 낮출수가 있었다. 가장 알맞는 실험조건은 다음과 같다. : 0.1M KCl-0.01M 인산염 지지전해질, pH 7, 석출전위 0.00V, 그리고 석출시간 3분이었다. 이 조건에서 검출한계는 $3{\times}10^{-7}M$ (8ppb) $CN^-$이다.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.845-849
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• 2010

A gold nanoparticles modified carbon paste electrode (GN-CPE) has been used for the determination of atenolol (ATN) in drug formulations by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronocoulometric methods. The results revealed that the modified electrode shows an electrocatalytic activity toward the anodic oxidation of atenolol by a marked enhancement in the current response in buffered solution at pH 10.0. The anodic peak potential shifts by -80.0 mV when compared with the potential using bare carbon paste electrde. A linear analytical curve was observed in the range of $1.96\;{\times}\;10^{-6}$ to $9.09\;{\times}\;10^{-4}\;mol\;L^{-1}$. The detection limit for this method is $7.3\;{\times}\;10^{-8}\;mol\;L^{-1}$. The method was then successfully applied to the determination of atenolol in tablets and human urine. The percent recoveries in urine ranged from 92.0 to 110.0%.

• 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.