• Toxicological Research
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• v.29 no.4
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• pp.293-298
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• 2013

A method of detecting lead was developed using square wave anodic stripping voltammetry (SWASV) with DNA-carbon nanotube paste electrode (CNTPE). The results indicated a sensitive oxidation peak current of lead on the DNA-CNTPE. The curves were obtained within a concentration range of 50 $ngL^{-1}-20mgL^{-1}$ with preconcentration time of 100, 200, and 400 sec at the concentration of $mgL^{-1}$, ${\mu}gL^{-1}$, and $ngL^{-1}$, respectively. The observed relative standard deviation was 0.101% (n = 12) in the lead concentration of 30.0 ${\mu}gL^{-1}$ under optimum conditions. The low detection limit (S/N) was pegged at 8 $ngL^{-1}$ ($2.6{\times}10^{-8}M$). Results showed that the developed method can be used in real-time assay in vivo without requiring any pretreatment and pharmaceutical samples, and food samples, as well as other materials requiring water source contamination analyses.

• 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.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.443-449
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• 2012

A investigation of electrochemical analysis of antibiotics Neomycin ($C_{23}H_{46}N_6O_{13}$) was searched using electrochemical square wave (SW) stripping and cyclic voltammetry (CV) using working sensor of the modified carbon nanotube combination electrodes, optimum diagnostic parameters were searched by anodic stripping, final conditions were attained to working range of 1.0-14.0 ng/L, detection limit (S/N) was found to be 0.6 ng/L. The developed method was discovered to be fitting in quality control in the food, pharmaceutical and other manufacturing sectors.

• Journal of Powder Materials
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• v.19 no.4
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• pp.297-303
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• 2012

In this study, voltammetry system for realizing high sensitivity nano-labeled sensor of detecting heavy metals was designed, and optimal system operating conditions were determined. High precision digital to analog converter (DAC) circuit was designed to control applied unit voltage at working electrode and analog to digital converter (ADC) circuit was designed to measure the current range of $0.1{\sim}1000{\mu}A$ at counter electrode. Main control unit (MCU) circuit for controlling voltammetry system with 150 MHz clock speed, main memory circuit for the mathematical operation processing of the measured current value and independent power circuit for analog/digital circuit parts to reduce various noise were designed. From result of voltammetry system operation, oxidation current peaks which are proportional to the concentrations of Zn, Cd and Pb ions were found at each oxidation potential with high precision.

• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.505-509
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• 2012

In this study, we investigate the use of new carbon nanotube paste electrode (CNPE) for promoting the detection of lead (Pb) heavy metal in the a drinkable water, which negatively affects human brain and nerve system. For the evaluations, CNPE is served as a working electrode, while sensitivity and limit of detection (LOD) of Pb are measured in DI and tap water based electrolytes using squarewave anodic stripping voltammetry (SWASV). As a result of that, in the 25~150 ppb range of $Pb^{2+}$ ions, its sensitivity and calculated LOD are $12.85\;{\mu}A/{\mu}M$ and 26 ppb in DI water based 0.1 M $H_{2}SO_{4}$ electrolyte while they are $10.36\;{\mu}A/{\mu}M$ and 38 ppb electrolytes respectively. In addition, experimentally measured LOD values of Pb are 4 ppb and 10 ppb in the two water electrolytes. The stripping of $Pb^{2+}$ ion is also controlled by surface reaction. Our experimental data are then compared with those of other already published references. With the comparison, it is proved that our electrode outperforms other electrodes in terms of the sensitivity and LOD of trace Pb metal.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.626-630
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• 2012

Diagnosis with an ex-vivo gold sensor was done using a modified fluorine-doping sensor, and cyclic voltammetry (CV) redox potentials of 0.4 V anodic and -0.2 V cathodic were obtained. Both peak currents were optimized using square-wave (SW) stripping voltammetry, and an analytical working range of 10-80 ug/L SW was attained. The precision of the 10-mg/L Au was 0.765 (n=8) RSD under the optimum conditions, and the analytical detection limit approached 0.006 ug/L (S/N=3) with only a 60 sec accumulation time. The developed method was used to examine the mouse droppings for medicinal diagnosis.

• Journal of the Korean Chemical Society
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• v.51 no.5
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• pp.412-417
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• 2007

A simple prepared paste electrode (PE) of DNA immobilized on a carbon nanotube was utilized for monitoring the antibacterial agent oxytetracycline (OTC), using square-wave anodic stripping voltammetry (SWASV) and cyclic voltammetry (CV). Given these conditions, SWASV and CV working ranges were observed within 1-10 ngL-1 OTC. In the SWASV and CV for OTC concentrations of 0.1 mgL-1, the relative standard deviations (n=15) were 0.068 and 0.067, respectively. At the optimized condition, the detection limit was found to be 0.4 ngL-1 OTC. This method was applied to the hatchery fish tissue.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.515-519
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• 2007

Neurotransmitter glycine in the nano gram range was analyzed using a paste electrode (PE) in cyclic voltammetry (CV) and square-wave stripping voltammetry (SWSV). An anodic peak caused by oxidation of the glycine ion appeared at the 0.4 V (versus Ag/AgCl/KCl) potential in a 0.1 M NH4H2PO4 electrolyte solution. At optimized conditions, the working range of the SWSV and CV concentration was found to be 5-60 ngL-1 glycine; precision of R2 = 0.9816 (SWSV) and 0.9986 (CV); and detection limit of 0.65 ngL-1 (5.82 × 10-12 molL-1) (S/N = 3). The optimized conditions were applied to an assay in a fish brain tissue and a living brain cell in real time.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2949-2954
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• 2010

Ionic liquid-functionalized ordered mesoporous silica SBA-15 modified carbon paste electrode (CISPE) was fabricated and its electrochemical performance was investigated by cyclic voltammetry, electrochemical impedance spectra. The electrochemical behavior of $Cd^{2+}$, $Pb^{2+}$, $Cu^{2+}$ and $Hg^{2+}$ at CISPE was studied by differential pulse anodic stripping voltammetry (DPASV). Compared with carbon paste electrode, the stripping peak currents had a significant increase at CISPE. Under the optimized conditions, the detection limits were $8.0{\times}10^{-8}\;M$ ($Cd^{2+}$), $4.0{\times}10^{-8}\;M$ ($Pb^{2+}$), $6.0{\times}10^{-8}\;M$ ($Cu^{2+}$), $1.0{\times}10^{-8}\;M$ ($Hg^{2+}$), respectively. Furthermore, the present method was applied to the determination of $Cd^{2+}$, $Pb^{2+}$, $Cu^{2+}$ and $Hg^{2+}$ in water samples and people hair sample.

• Journal of Electrochemical Science and Technology
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• v.4 no.1
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• pp.1-18
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• 2013

Gallium is an important element in the production of a variety of compound semiconductors for optoelectronic devices. Gallium has a low melting point and is easily oxidized to give oxides of different compositions that depend on the conditions of solutions containing Ga. Gallium electrode reaction is highly irreversible in acidic media at the dropping mercury electrode. The passive film on a gallium surface is formed during anodic oxidation of gallium metal in alkaline media. Besides, some results in published reports have not been consistent and reproducible. An increase in the demand of intermetallic compounds and semiconductors containing gallium gives rise to studies on electrosynthesis of them and an increase of gallium concentration in the environment with various application of gallium causes the development of electroanalysis tools of Ga. It is required to understand the electrochemistry of Ga and to predict the electrochemical behavior of Ga to meet these needs. Any review papers related to the electrochemistry of gallium have not been published since 1978, when the review on the subject was published by Popova et al. In this study, the redox behavior, anodic oxidation, and electrodeposition of gallium, and trace determination of gallium by stripping voltammetries will be reviewed.