• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.889-893
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• 1992

A very sensitive adsorptive stripping voltammetric method is studied on the gallium-morin complex at a hanging mercury drop electrode (HMDE) in 0.1 M acetate buffer solution. The effects of various analytical conditions are discussed on the reduction peak current of the adsorbed complex on the suface of HMDE. Interferences by other trace metals and surfactant are also discussed. Detection limit is 1.7 nM of gallium with 60 seconds deposition time, and the relative standard deviation (n = 7) at 4 ${\mu}$g/l gallium is 2.8%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.569-572
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• 2001

Selective, highly stable determination of epinephrine(adrenalin) was achieved in cyclic voltammetric measurement carried out at electrochemically treated conductive boron-doped diamond electrode. Boron-doped diamond electrodes were prepared on single crystal Si wafers by microwave plasma chemical vapor deposition and B$_2$O$_3$ was dissolved in acetone/methanol(1:1) mixture solution so that the B/C weight ratio ca. 10$^3$ppm.. Epinephrine is a kind of catecholamines, which secreted from adrenal marrow cells. The serious problem to detection of epinephrine is the interference phenomena of electroactive constituent, including AA. In this study, electrochemical treatment of BDD was carried out to discriminate between epinephrine and AA responses. Experimental results showed that the peak potential of AA oxidation shift to the positive direction and the oxidation peak of epinephrine was unchanged. The effect of electrochemical treatment was maintained up to 40hrs.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.167-169
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• 2002

Selective, highly stable determination of serotonin was achieved in cyclic voltammetric measurement carried out at electrochemically treated conductive boron-doped diamond electrode. Boron-doped diamond electrodes were prepared on single crystal Si wafers by microwave plasma chemical vapor deposition and $B_2O_3$ was dissolved in acetone/methanol(9:1) mixture solution so that the B/C weight ratio ca. $10^4ppm$. Serotonin is a kind of indoleamines, which secreted from adrenal marrow cells. The serious problem to detection of serotonin is the interference phenomena of electroactive constituent, including AA. In this study, electrochemical treatment of HDD was carried out to discriminate between serotonin and AA responses. Experimental results showed that the peak potential of AA oxidation shift to the positive direction and the oxidation peak of serotonin was unchanged.

• 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%.

• Journal of Electrochemical Science and Technology
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• v.9 no.4
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• pp.292-300
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• 2018

The electrocatalytic oxidative behavior of an antiarrhythmic drug, procainamide hydrochloride (PAH) at the gold electrode surface has been examined using different voltammetric methods like cyclic, linear-sweep and differential pulse voltammetry. Voltammograms obtained in this study reveal that the electrode exhibit excellent electrocatalytic activity towards oxidation of the drug. The parameters that can affect the peak current at different pH, scan rate and concentration were evaluated. The number of electrons transferred was calculated. The current displayed a wide linear response ranging from 0.5 to $30.0{\mu}M$ with a limit of detection of 56.4 nM. The impact of potential interfering agents was also studied. The electrode displayed wide advantages such as simple sample preparation, appreciable repeatability, reproducibility and also high sensitivity. Furthermore, the feasibility of the proposed method was successfully demonstrated by determining PAH in the spiked human biological sample.

• Journal of the Korean Electrochemical Society
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• v.4 no.3
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• pp.109-112
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• 2001

An activated carbon paste electrode was modified with the N-Hydroxysuccinimide(NHS) layer and applied to determine the dopamine in the presence of an excess ascorbic acid using square-wave voltammetry. The electrochemical properties of the modified electrode were examined in the solution containing dopamine/ascorbic acid using cyclic voltammetry(CV): the separation between the oxidation peaks of dopamine and ascorbic acid was largely dependent on the pH of the sample solution and became maximum at pH 4.0. Hence, the square-wave voltammetric determination of dopamine was carried out in a pH 4.0, 100mM phosphate buffer saline(PBS) containing 140mM NaCl. The detection limit and response slop were improved from $1.0{\mu}M\;to\;5.0\times10^{-2}{\mu}M\;and\;from\;0.93{\mu}A/{\mu}M\;to\;6.1{\mu}A/{\mu}M$, respectively, upon modification of the electrode surface by NHS.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.177-180
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• 2003

A glassy carbon electrode(GCE) modified with nafion-DTPA-glycerol was used for the highly selective and sensitive determination of a trace amount of Cu$\^$2+/. Various experimental parameters, which influenced the response of nafion-DTPA-glycerol modified electrode to Cu$\^$2+/, were optimized. The copper(II) was accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface was characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry, A linear range was obtained in the concentration range 1.0${\times}$10$\^$-8/M∼1.0${\times}$10$\^$-6/M Cu(II) with 7 min preconcentration. Further, when an approximate amount of lead(II) is added to the test solution, nafion-DTPA-glycerol modified glassy carbon electrode has a dynamic range of 2 orders magnitude(1.0${\times}$10$\^$-9/M∼1.0${\times}$10$\^$-7/M). The detection limit(3 $\sigma$) was as low as 5.0${\times}$10$\^$-6/M(0.032ppb). The interferences from other metal ions could be reduced by adding KCN into the sample solutions. This method was applied to the determination of coppe,(II) in certified reference material(3.23${\times}$10$\^$-7/M, 21ppb), sea water(9.50${\times}$10/sup-7/M, 60ppb). The result agrees satisfactorily with the value measured by Korea Research Institute of Standard and Science.

• Analytical Science and Technology
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• v.10 no.6
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• pp.427-432
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• 1997

A selective method for the determination of iron(III) ion with a sodium dodecyl sulfate(SDS) modified glassy carbon electrode was proposed. It was based on the electrostatic attraction and complexation of the SDS modifier, $(DS^-)_n-Fe^{3+}$. The determination of iron(III) ion was performed by a differential pulse voltammetry(DPV), and the reduction peak potential of $(DS^-)_n-Fe^{3+}$ was +0.466(${\pm}0.002$)V vs. Ag/AgCl. For the determination of iron(III) ion, a linear calibration curve was obtained within the iron(III) ion concentration range of $0.50{\times}10^{-5}{\sim}10{\times}10^{-5}mol/L$, and the detection limit was $0.14{\times}10^{-5}mol/L$. $Cu^{2+}$, $Ni^{2+}$, $Co^{2+}$, $Pb^{2+}$, $Zn^{2+}$, and $Mn^{2+}$ showed little or no effect on the determination of iron(III) ion, respectively. But, ion such as each $CN^- $ and $SCN^-$ interfered seriously.

• Journal of the Korean Chemical Society
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• v.40 no.5
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• pp.341-346
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• 1996

Electrochemical determination of iodide was carried out by stripping voltammetry with a $(Cin)Cu(NO_3)_2$ modified-carbon paste electrode. Iodide was coordinated onto the electrode surface containing $(Cin)Cu(NO_3)_2$ via ion exchange. The oxidation peak potential of incorporated iodide was ＋0.72 V. The optimum analytical conditions for the determination of iodide were investigated using linear sweep voltammetry. Optimum conditions for the electrochemical determination of iodide were as follows: i) A predeposition solution was 0.1 M $KNO_3.$ ii) The deposition time was 10 min. iii) The composition of the electrode was 40% (w/w). The detection limit for iodide was $1.0{\times}10^{-6}M$ and the relative standard deviation was ${\pm}5.5%\;in\;2.0{\times}10^{-5}M$(four repetitions). The interference effect of other anions were also investigated. $Cl^-,\;Br^-,\;C_2O_4^{2-},\;and\;ClO_4^-$ ions do not interfere for the determination of iodide. When $SCN^-$ was added to the deposition solution, the oxidation peak current of iodide ion was decreased roughly 32%.

• Journal of the Korean Chemical Society
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• v.43 no.1
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• pp.36-41
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• 1999

The adsorptive stripping voltammetric determination method of trace germanium (IV) using mercaptoacetic acid as a ligand was studied. Optimal conditions were found to be 0.25 M NaCl solution (pH 6.0) containing mercaptoacetic acid concentration of $5.0{\times}10^{-6}M$. The peak potential appeared at - 1.402 V vs. Ag/AgCl. Effects of sodium chloride concentration, mercaptoacetic acid concentration, and accumulation time for the complex of Ge(IV)-Mercaptoacetic acid on the peak current were studied. Amberlite IRC-718 chelating resin was applied to the separation of Ge(IV) from other metal ions.