• Title/Summary/Keyword: Cathodic stripping voltammetry

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Determination of Traces of Selenium in Plant Materials by Cathodic Stripping Voltammetry (Cathodic Stripping Voltammetry법에 의한 식물체 중 극미량 셀렌의 분석)

  • 문동철;홍성화;박만기;김중기;이광우
    • YAKHAK HOEJI
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    • v.29 no.3
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    • pp.144-151
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    • 1985
  • Cathodic stripping voltammetric determination of traces of selenium in plant samples was studied. Stripping peak of selenium (IV) from Cu-Se intermettalic deposit in acidic media containing copper (II) ion is specific, highly sensitive and well defined, is successfully used for the quantitative determination of selenuin down to the level of 1ng/ml. Sample is burnt in a calorimeter bomb under the oxygen pressure of 40atm. and the selenium is absorbed in 0.1M NaOH. After the solution is filtrated, concentrated and acidified with HCl, then passed through a column of cation exchange resin in the $H^{+}$ form(Dowex 50X-8). The column eluate is analyzed for selenium by differential pulse cathodic stripping voltammetric method. Analytical results of selenium for NBS SMR is well agreement with the certified values. Results are given for a series of plant materials.

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Determination of Ultra Trace Levels of Copper in Whole Blood by Adsorptive Stripping Voltammetry

  • Attar, Tarik;Harek, Yahia;Larabi, Lahcen
    • Journal of the Korean Chemical Society
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    • v.57 no.5
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    • pp.568-573
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    • 2013
  • A selective and sensitive method for simultaneous determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The procedure involves an adsorptive accumulation of Cu(II)-ETSC (4- ethyl-3-thiosemicarbazide) on a hanging mercury drop electrode, followed by a stripping voltammetry measurement of reduction current of adsorbed complex at about -715 mV. The optimum conditions for the analysis of copper (II) ion are : pH 10.3, concentration of 4-ethyl-3-thiosemicarbazide $3.25{\times}10^{-6}$ M and an accumulation potential of -100 mV. The peak current is proportional to the concentration of copper over the range 0.003-125 ng/mL with a detection limit of 0.001 ng/mL and an accumulation time of 60 s. Moreover, with the use of the proposed method, there is a considerable improvement in the detection limit, the linear dynamic range and the deposition time, compared with the methods of adsorptive stripping voltammetry for the determination of copper. The developed method was validated by analysis of whole blood certified reference materials.

Analysis of Arsenic(III) by the Cathodic Stripping Voltammetry (음극 벗김 전류법을 이용한 비소(III) 분석에 관한 연구)

  • Yun, Young Ja;Lee, Hyung Sook;Ko, Weon Bae;Kim, Chung Hee
    • Analytical Science and Technology
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    • v.5 no.4
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    • pp.417-423
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    • 1992
  • The effects of metal ions on the arsenic(III) stripping peak were examined by the cathodic stripping voltammetry. The reduction stripping peak potential and current of arsenic(III) value were -0.79V(vs. Ag/AgCl). $0.86{\mu}A$ by using 0.1N-hydrochloric acid solution. When 10 times of Cu(II) was added to the solution, the reduction stripping peak potential of arsenic(III) was the value of -0.84V(vs. Ag/Cl), which showed a good agreement with theoretical value -0.84V(vs. Ag/Cl) by using 0.1N hydrochloric acid solution. Lead(II) and copper(II) increased the stripping peak heigh of arsenic(III), Among them, the copper(II) extremely enhanced it.

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Determination of Cyanide Ion in the Presence of Sulfide Ion by Differential Pulse Cathodic Stripping Voltammetry (시차펄스 음극벗김 전압전류법에 의한 황화이온의 존재하에서 시안화이온의 정량)

  • Park, Se Yeon;Kwon, Young Soon
    • Analytical Science and Technology
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    • v.6 no.1
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    • pp.47-55
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    • 1993
  • The quantitative determination of trace cyanide ion in the presence of sulfide ion has been studied by addition of cupric ion using differential pulse Cathodic Stripping Voltammetry. The detection limit of cyanide ion in the presence of $5.0*10^{-5}M$ sulfide ion and $1.0*10^{-3}M$ cupric ion was $2.0*10^{-7}M$ in KCI-Phosphate buffer(pH=7.0) at accumulation potential -0.30V and accumulation time 3.0 min.

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Mercury Ion Monitoring in Mercury Plating Bath by Anodic Stripping Voltammetry

  • Park, Mijung;Yoon, Sumi;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.7 no.3
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    • pp.241-244
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    • 2016
  • Anodic stripping voltammetry (ASV) is successfully applied in mM level detection of mercury ion in an electroplating bath which is currently used in preparing a cathodic electrolyzer. Glassy carbon electrode is used for the detection and the optimum condition obtained is 10 s deposition at −1.4 V vs. Ag/AgCl and stripping by scanning from −1.4 to +0.4 V vs Ag/AgCl at 50 mV/s. By applying the method, the mercury ion concentration in the electroplating bath could be successfully monitored during the plating.

Increased Sensitivity in Cyanide Measurement by Differential-Pulse Cathodic Stripping Voltammetry (시차펄스 음극벗김 전압전류법에 의한 시안이온 측정의 감도향상)

  • Na, Moon-Son;Kwon, Young-Soon;Czae, Myung-Zoon
    • Journal of the Korean Chemical Society
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    • v.32 no.2
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    • pp.130-134
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    • 1988
  • Direct differential-pulse cathodic stripping voltammetry on mercury electrode (HMDE) provides a sensitive technique for low level cyanide measurement in distilled and sulfide free solution. Cyclic voltammetry revealed the forming and redissolution reactions were reversible at pH 7 in 0.1M KCl-0.01M phosphate supporting electrolyte. The analytical conditions have been optimized. With deposition time of 3 min at deposition potential 0.00V(vs. Ag/AgCl) in this medium of pH7, quite reproducible and linear calibration curve was obtained down to $3{\times}10^{-7}M$ (8ppb) $CN^-$ which was the detection limit.

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Determination of Thioglycolic acid in the presence of Copper(II) by Adsorptive Stripping Voltammetry (흡착 벗김 전압전류법에 의한 구리이온(II) 존재하에서 티오글리콜산의 정량)

  • Hong, Mi-Jeong;Kwon, Young-Sun
    • Analytical Science and Technology
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    • v.8 no.1
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    • pp.25-32
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    • 1995
  • Determination method of trace thioglycolate has been studied by adsorptive stripping voltammetry. Copper(II)-thioglycolate complex is adsorbed at the hanging mercury drop electrode and stripped during cathodic scan. Electrolyte was used pH 6.5 phosphate and pH 9.5 borate buffer solutions. Optimal conditions were a copper(II) concentration $1{\times}10^{-4}M$, an adsorption accumulation potential -0.2V, an adsorption accumulation time 60 sec and a scan rate 20mV/sec. A detection limit of $1{\times}10^{-9}M$ thioglycolate was obtained. The method was applied to the determination of thioglycolate in cold wave fluids and depilating creams.

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Diagnostic Ex-vivo Assay of Metal Gold in Rat Droppings Using Voltammetry

  • Ly, Suw-Young;Lee, Chang-Hyun
    • 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.

Adsorptive Behavior of Catechol Violet and Its Thorium Complex on Mercury Electrode in Aqueous Media

  • Rabia Mostafa K. M.
    • Journal of the Korean Electrochemical Society
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    • v.7 no.1
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    • pp.9-15
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    • 2004
  • Cyclic voltammetry and chronocoulometry have been used for characterization of catechol violet (CV) at the hanging mercury drop electrode in acetic acid-sodium acetate buffer solution. At pH 2.94 a nearly symmetric cyclic voltammetric wave due to an irreversible weak adsorption of CV on mercury was obtained at concentration of $0.53{\mu}mol\;dm ^{-3}$. Under these conditions, CV adsorbes in a monolayer. Upon increasing the concentration, the symmetry of the wave decreases; it can be attributed to a mixed diffusion adsorption process. The amount of the adsorbed catechol violet on the HMDE expressed as surface concentration as well as the surface areaf occupied by one molecule$(\sigma)$ were calculated. It was found that the values obtained for f and o utilizing cyclic voltammetric and chrono-coulometry are almost identical. A 1:1 and 1:2 Th (IV)-CV complexes are formed on addition of thorium (IV) to catechol violet. These complexes are adsorbed and reduced on the HMDE at more negative potentials than the peak potential of free CV, Using the square-wave (SW) technique, the adsorptive cathodic stripping voltammetry, ACSV, of these complexes was studied. It was found that the SW-ACSV of Th(IV)-CV can be applied to the determination of thorium at the nanomole level. Optimum conditions and the analytical method of determination were presented and discussed.