• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.485-488
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• 1989

A carbon paste coated-wire ion-selective electrode for chloride (carbon chloride-CWE) was constructed using epoxy resin, ion-exchanger and carbon powder as a polymer membrane. Its utility, the composition of a polymer membrane, the response characteristics, and the selectivity were examined and applied to the environmental water analysis. The carbon chloride-CWE was prepared using a silver wire, which was covered with silver chloride and then coated with epoxy resin into which chloride ion-exchanger and carbon powder were previously incorporated in advance. The response of the carbon chloride-CWE was Nernstian for $1.0{\times}10^{-2}-2{\times}10^{-5}$ M chloride and the useful pH range from $10^{-2} M Cl- to 10^{-4} M Cl^-$ was 3.0-9.0. Furthermore, the selectivity of chloride over iodide, bromide, and cyanide was much improved compared with those for a solid state epoxy body chloride electrode and a liquid membrane chloride electrode. The carbon chloride-CWE was applied to determine Cl^-$ in tap and ground water. The obtained results were in good agreement with those by the established methods such as spectrophotometric or other chloride-selective electrode methods.

• Analytical Science and Technology
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• v.8 no.4
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• pp.611-615
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• 1995

The design of appropriate chemically modified electrodes should allow development of new voltammetric measurement schemes with enhanced selectivity and sensitivity. Microorganism like algae has high ability to trap toxic and heavy metal ions and different affinities for metal ions. A copper(II) ion-selective carbon paste electrode was constructed by incorporating alga Anabaena into a conventional carbon paste mixture, and then the film of 10% Nafion was coated to avoid the swelling of the electrode surface. Copper ion could be deposited at the 25% algamodified electrode for 15 min without the applied potential while stirring the solution by only immersing the electrode in a buffer (pH 4.0) cot1taining copper(II). Temperature was controlled at $35^{\circ}C$. After preconcentration was carried out the electrode was transferred to a 0.1 M potassium chloride solution and was reduced at -0.6 volt at $25^{\circ}C$. The differential pulse anodic stripping voltammetry was employed. A well-defined oxidation peak could be obtained at -0.1 volt (vs SCE). In five deposition / measurement / regeneration cycles, the responses were reproducible and relative standard deviations were 3.3% for $8.0{\times}10^{-4}M$ copper(II). Calibration curve for copper was linear over the range from $2.0{\times}10^{-4}M$ to $1.0{\times}10^{-3}M$. The detection limit was $7.5{\times}10^{-5}M$. Studies of the effect of diverse ions showed that the coexisting metal ions had little or no effect for the determination of copper. But anions such as cyanide. oxalate and EDTA seriously interfered.

• Analytical Science and Technology
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• v.12 no.2
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• pp.171-175
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• 1999

Carbon paste electrodes, modified with podands containing more than two sulfur atoms, have been employed for the voltammetric determination of Ag(I) ion from aqueous solution. The voltammetric response was characterized with respect to paste composition, preconcentration method, kind of anion, variation of pH, Ag(I) ion concentration, and possible interferences. Linear calibration curves were obtained for Ag(I) ion concentration ranging from $1.0{\times}10^{-6}$ to $9.0{\times}10^{-5}M$, and detection limit was $5.0{\times}10^{-7}M$.

• Analytical Science and Technology
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• v.15 no.1
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• pp.91-95
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• 2002

Carbon paste electrodes, modified with 5,6,14,15-dibenzo-1,4-dioxa-8,12-diazacyclopentadeca-5,14-diene containing different ligating atoms of oxygen and nitrogen, have been employed for the voltammetric determination of Ag(I) ion from aqueous solution. The voltammetric response was characterized with respect to paste composition, preconcentration method, kind of anion, variation of pH, Ag(I) ion concentration, and possible interferences. Linear calibration curves were obtained for Ag(I) ion concentration ranging from $3.0{\times}10^{-6}M$ to $8.0{\times}10^{-5}M$, and detection limit was $8.5{\times}10^{-7}M$.

• Journal of the Korean Electrochemical Society
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• v.17 no.2
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• pp.130-137
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• 2014

A strip sensor based on $PbO_2$/carbon paste electrode was prepared by a screen-printing method, and employed to electrochemically determine the concentration of fruit sweeteners(i.e. glucose, sucrose, and fructose). The $PbO_2$/carbon paste electrode could monitor electrocatalytic oxidation of organic compounds such as carbohydrates, and measure the levels of natural sweeteners without enzyme. Severe interference from ascorbic acid was effectively reduced by modifying the electrode surface with a Nafion membrane. The response level of the Nafion/$PbO_2$/carbon paste electrode increased in the order of fructose, sucrose, and glucose, which corresponds to the order of sweetness perceived by humans.

• Analytical Science and Technology
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• v.16 no.6
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• pp.504-508
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• 2003

A carbon paste electrode was constructed with peroxidase extracted from Horseradish and the variation of the response of the sensor with pH was investigated. Current profiles showed two highest sensitivities at two pH values respectively. In addition, two bands were observed in the electrophoretic expansion. A coincidence of the two experimental results added support to the possibility that the biosensor has two different isozymes. Assuming that current profiles are the sum of two gaussians, we deconvoluted them and determined the optimum pH of peroxidase isozymes.

• Journal of the Korean Chemical Society
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• v.38 no.10
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• pp.734-740
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• 1994

Electrochemical determination of Ag(I) ion was carried out by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) with the carbon paste electrode (CPE) containing cinchonidine. The detection limit for Ag(I) ion was shown to be $1.0 {\times}10^{-6}$ M in conventional CV and up to $8.0{\times}10^{-9}$ M (${\pm}$0.6%) using DPV. The optimum analytical condition of Ag(I) ion was determined as follows: pH 7, 20 minutes of deposition time, and 50% (w/w) cinchonidine to carbon powder composition of electrode. The interference effect of various metal ions added to the deposition solution was also studied. The peak current of Ag(I) ion except Hg(II) ion was decreased roughly 25% compare to Ag(I) ion only. When Mn(II) ion was present in sample solution at pH 9, shown a large interference effect.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.114-118
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• 2011

Even though the carbon paste electrode bound with mineral oil is useful for research about the characteristics of enzymes, it remains far from practical uses because the lack of mechanical hardness limits its practical use. When the rubber liquefied in toluene was used as a binder of carbon powder in lab, it is confirmed that the mechanical robustness of the electrode is guaranteed. In order to confirm whether it shows quantitative electrochemical behaviors or not, its kinetic parameters, e.g. the symmetry factor (${\alpha}=0.28$), the exchange current density ($i_0=4.06{\mu}A/cm^2$), the capacity of the double layer ($C_d=2.11{\times}10^{-3}F$), the Michaelis constant ($K_M=2.45{\times}10^{-3}M$), and the time constant (${\tau}_B=0.077sec$) were investigated. Our experimental observations prove that the chloroprene rubber is a promising binder for the practical use of a carbon paste electrode.

• 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.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.227-231
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• 1999

Disposable, amperometric glucose sensor was constructed using platinised carbon paste electrode. The sensor response was studied by amperometry and cyclic voltammetry applying sample solutions on the strip-type electrode. Platinization of screen-printed carbon paste electrode effectively improved the electrochemical reversibility of a mediator and the analytical characteristics of the sensor. The heterogeneous rate constant for $[Fe(CN)_6]^{4-/3-}$ was $1.45\times10^{-2}cm{\cdot}s^{-1}$. An applied potential of 0.3V vs. Ag/AgCl resulted in the best selectivity for glucose. The apparent Michaelis-Menten constant for glucose on the strip sensor, $K_m^{app}$, was 24.5 mM. To evaluate the analytical performance of the glucose sensor strip, a correlation study was performed with the NOVA S.P, Ultra M analyzer for 30 serum samples containing $80\~297mg/dL$ of glucose: the correlation coefficient value was 0.983. It can be seen that the strip sensor has satisfactory precision and accuracy.