• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.206-213
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• 2019

The development of simple methods for As detection has received great attention because As is a toxic chemical element causing environmental and health-related issues. In this work, the effect of nanostructures of Au electrodes on their electroanalytical performance during As detection was investigated. Different Au nanostructures with various surface morphologies such as nanoplate Au, nanospike Au, and dendritic Au structures were prepared, and their electrochemical behaviors toward square-wave anodic stripping voltammetric As detection were examined. The difference in intrinsic efficiency for As detection between nanostructured and flat Au electrodes was explained based on the crystallographic orientations of Au surfaces, as examined by the underpotential deposition of Pb. The most efficient As detection performance was obtained with nanoplate Au electrodes, and the effects of the pre-deposition time and interference on As detection of the nanoplate Au electrodes were also investigated.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.336-343
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• 2000

Purpose: Thallous-201 chloride produced at Korea Cancer Center Hospital(KCCH) is used in detecting cardiovascular disease and cancer. Thallium impurity can cause emesis, catharsis and nausea, so the presence of thallium and other metal impurities should be determined. According to USP and KP, their amounts must be less than 2 ppm in thallium and 5 ppm in total. In this study, the detection method of trace amounts of metal impurities in $[^{201}Tl]$TICI injection with polarography was optimized without environmental contamination. Materials and Methods: For the detection of metal impurities, Osteryoung Square Wave Stripping Voltammetry method was used in Bio-Analytical System (BAS) 50W polarograph. The voltammetry was composed of Dropping Mercury Electrode (DME) as a working electrode, Ag/AgCl as a reference electrode and Pt wire as a counter electrode. Square wave stripping method, which makes use of formation and deformation of amalgam, was adopted to determine the metal impurities, and pH 7 phosphate buffer was used as supporting electrolyte. Results: Tl, Cu and Pb in thallous-201 chloride solution were detected by scanning from 300 mV to -800 mV Calibration curves were made by using $TINO_3,\;CuSO_4\;and\;Pb(NO_3){_2}$ as standard solutions. Tl was confirmed at -450 mV peak potential and Cu at -50 mV Less than 2 ppm of Tl and Cu was detected and Pb was not detected in KCCH-produced thallous-201 chloride injection. Conclusion: Detection limit of thallium and copper is approximately 50 ppb with this method. As a result of this experiment, thallium and other metal impurities in thallous-201 chloride injection, produced at Korea Cancer Center Hospital, are in the regulation of USP and KP Polarograph could be applied for the determination of metal impurities in the quality control of radiopharmaceuticals conveniently without environmental contamination.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.325-331
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• 2009

We studied square-wave stripping voltammetry (SWV) to analyze quantitatively rutin contained in transparent skin-lotion using graphite electrode. The optimum analytical conditions for quantitative analysis of rutin were determined and the linear range was obtained of $1\;{\sim}\;8\;{\mu}g/mL$. The relative standard deviation of fifteen times repetition measurement for $0.1\;{\mu}g/mL$ of rutin was 0.080 and the detection limit was $0.01\;{\mu}g/mL$, respectively. We considered that this study could be used for quantitative analysis of active components contained in cosmetics.

• Toxicological Research
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• v.29 no.3
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• pp.211-215
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• 2013

The trace toxic metal copper was assayed using mercury immobilized on a carbon nanotube electrode (MCW), with a graphite counter and a reference electrode. In this study, a macro-scale convection motor was interfaced with a MCW three-electrode system, in which a handmade MCW was optimized using cyclic- and square-wave stripping voltammetry. An analytical electrolyte for tap water was used instead of an expensive acid or base ionic solution. Under these conditions, optimum parameters were 0.09 V amplitude, 40 Hz frequency, 0.01 V incremental potential, and a 60-s accumulation time. A diagnostic working curve was obtained from 50.0 to 350 ${\mu}g/L$. At a constant Cu(II) concentration of 10.0 ${\mu}g/L$, the statistical relative standard deviation was 1.78% (RSD, n = 15), the analytical accumulation time was only 60 s, and the analytical detection limit approached 4.6 ${\mu}g/L$ (signal/noise = 3). The results were applied to non-treated drinking water. The content of the analyzed copper using 9.0 and 4.0 ${\mu}g/L$ standards were 8.68 ${\mu}g/L$ and 3.96 ${\mu}g/L$; statistical values $R^2$ = 0.9987 and $R^2$ = 0.9534, respectively. This method is applicable to biological diagnostics or food surveys.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.302-310
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• 2012

Bio assay of mercury and cadmium ions were searched using voltammetric analysis using DNA doped carbon nanotube paste electrodes (DCP). The square-wave stripping voltammetryic optimized results indicated working ranges of 1-10.0 $ngL^{-1}$ and 20-100 $ugL^{-1}$, Hg(II) Cd(II) within an accumulation time of 120 seconds, in 0.1-M phosphate buffer solutions of pH 6.3. The relative standard deviations of 5 $ngL^{-1}$ Hg(II) and Cd(II) that observed were 0.14 and 0.22% (n=12), respectively, using optimum conditions. The low detection limit (S/N) was pegged at 0.1 $ngL^{-1}$ ($4.9{\times}10^{-11}M$) Hg(II) and 0.2 $ngL^{-1}$ ($1.77{\times}10^{-10}M$) Cd(II). The developed methods can be applied to assays in biological fish kidneys and water samples.

• Analytical Science and Technology
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• v.24 no.3
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• pp.219-224
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• 2011

Voltammetric analysis of Cl(I) ion was performed using a metal gold (Au) electrode (AE) and a carbon nanotube electrode (CNTE). After the examination, the AE was found to have more sensitively detected Cl(I) than CNTE. The optimum analytical conditions for the cyclic voltammetry (CV) and the square wave (SW) stripping voltammetry were performed using AE. The detection limit of $6.5\;{\mu}g/L$ Cl(I) was attained. The developed techniques were compared with the common Cl meter and applied to water systems.

• Toxicological Research
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• v.31 no.2
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• pp.213-217
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• 2015

A voltammetric toxic metal of cadmium detection was studied using a fluorine doped graphite pencil electrode (FPE) in a seawater electrolyte. In this study, square wave (SW) stripping and chronoamerometry were used for determination of Cd(II) in seawater. Affordable pencils and an auxiliary electrode were used as reference. All experiments in this study could be performed at reasonable cost by using graphite pencil. The application was performed on the tissue of contaminated soil earthworm. The results show that the method can be applicable for vegetables and in vivo fluid or medicinal diagnosis.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1742-1746
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• 2008

Catechol and caffeine were simultaneously analyzed with a bismuth-immobilized carbon nanotube paste electrode (BPE) using square wave (SW) stripping voltammetry. Optimum analytical conditions were determined. Simultaneous working ranges of 100-1,500 $mgL^{-1}$ for caffeine and 5-75 $mgL^{-1}$ for catechol were obtained. In the separated cell systems, a working range of 0.1-2.1 $mgL^{-1}$ catechol with a correlation coefficient of 0.9935, and a working range of 10-210 $mgL^{-1}$ caffeine with a correlation coefficient of 0.9921 were obtained. A detection limit (S/N) of 0.15 $mgL^{-1}$ (7.7 ${\times}$ $10^{-7}$ M) and a detection limit of 0.02 $mgL^{-1}$ (1.82 ${\times}$ $10^{-7}$ M), respectively, manifested for catechol and caffeine. It was found that three macro-type electrode systems could be implanted in fish and rat neuro cells. For both ions, the ion currents were observed. The physiological impulse conditions and the neuronal thinking current were also obtained.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.208-215
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• 2006

A simply prepared graphite, pencil-type working electrode was utilized to monitor fenitrothion concentrations, using the cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry methods. The optimum conditions for analysis were sought. A very low detection limit was obtained compared to that obtained when other common voltammetry methods are used. The optimal parameters of the pencil-type electrode were found to be as follows: a pH of 3.7, a frequency of 500 Hz, an SW amplitude of 0.1 V, an increment potential of 0.005 V, an initial potential of -0.9V, and a deposition time of 500 sec. The analytical detection limit was determined to be 6.0 ngL-1 (2.16410-11 molL-1) fenitrothion at SW anodic and CV, and the relative standard deviation at the fenitrothion concentration of SW anodic 10 ugL-1 was 0.30% (n = 15) under the optimum conditions. Analysis was directly conducted through in-vivo real-time assay.

• Analytical Science and Technology
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• v.21 no.2
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• pp.129-134
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• 2008

Cyclic voltammetry (CV) and square wave stripping voltammetry (SW) analysis of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) using the double-stranded ds calf thymus (DNA) mixed in carbon nanotube paste electrode (PE) were provided. The optimum analytical conditions were determined and the peak potential was 0.2 V vs. Ag/AgCl. The linear working ranges of CV (50-75 ug/L) and SW (5-80 ng/L) were obtained. The precisions of RSD in the 10 ug/L was 0.086% (n=15) and the detection limit was 0.65 ng/L ($2.92{\times}10^{-12}M$) (S/N=3) with 300 s adsorption time at the optimum condition. The method was used to determine the presence of explosive chemicals in contaminated soil samples.