Voltammetric determination of gold using a carbon paste electrode modified with thiobenzanilide

Cai, Xiaohua; Kalcher, Kurt; Neuhold, Christian; Diewald, Wolfgang; Magee, R.J.

doi:10.1039/an9931800053

Cited by 28 publications

(14 citation statements)

References 9 publications

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“…A carbon-paste electrode was first reported by Kuwana and French in 1964, 8 and has been applied until now for preparing of chemically modified electrodes for several purposes, such as the determination of trace amounts of some substances, [9][10][11] as electrochemical sensors for the analysis on biologically important compounds, [12][13][14][15] for electrocatalysis, [16][17][18][19][20] etc. To construct chemically modified carbon-paste electrodes, various redox mediators have been used, such as organometallic compounds, for example, the ferrocenes, [21][22][23] phthalocyanines 24,25 and metalloporphyrins 26,27 and several organic mediators, including quinines, [28][29][30] phenotiazine, 31 etc.…”

Section: Introductionmentioning

confidence: 99%

Electrocatalytic Characteristics of a 1-[4-(Ferrocenyl ethynyl)phenyl]-1-ethanone Modified Carbon-Paste Electrode in the Oxidation of Ascorbic Acid

et al. 2003

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A carbon-paste electrode spiked with 1-[4-(ferrocenyl ethynyl)phenyl]-1-ethanone was constructed by the incorporation of 1-[4-(ferrocenyl ethynyl)phenyl]-1-ethanone in a graphite powder silicon oil matrix. It shown by cyclic voltammetry and double potential-step chronoamperometry, which this ferrocene derivative modified a carbon-paste electrode, can catalyze the ascorbic acid oxidation in an aqueous buffered solution. It has been found that under the optimum conditions (pH 7.00), the oxidation of ascorbic acid at the surface of this carbon paste modified electrode occurs at a potential of about 260 mV less positive than that of an unmodified carbon-paste electrode. The catalytic oxidation peak current was linearly dependent on the ascorbic acid concentration, and a linear calibration curve was obtained in the range of 6 × 10 -5 M -7 × 10 -3 M of ascorbic acid with a correlation coefficient of 0.9997. The detection limit (2σ) was determined to be 6.3 × 10 -5 M. This method was also used for the determination of ascorbic acid in some pharmaceutical samples, such as effervescent tablets, ampoules and multivitamin syrup, by using a standard addition method. The reliability of the method was established by a parallel determination against the official method.

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Section: Introductionmentioning

confidence: 99%

Electrocatalytic Characteristics of a 1-[4-(Ferrocenyl ethynyl)phenyl]-1-ethanone Modified Carbon-Paste Electrode in the Oxidation of Ascorbic Acid

et al. 2003

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“…For the stripping analysis of gold the unmodified carbon or platinum [1][2][3][4] and chemically modified carbon electrodes [5][6][7][8][9] have been used. At carbon and platinum electrodes the deposition of gold is hampered by the slow nucleation process [2].…”

Section: Introductionmentioning

confidence: 99%

Selective method for the determination of gold by anodic stripping voltammetry

Korolczuk

1996

Analytical and Bioanalytical Chemistry

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A highly selective method for the deter- mination of gold by anodic stripping voltammetry is described. For preconcentration a glassy carbon electrode, activated by deposition of small amounts of gold before the measurement, is proposed. The Au(3+) reduction process at such an electrode is effective starting with the potential +0.4 V vs. Ag/AgCl electrode. A linear dependence of the current of the gold stripping peak on the gold concentration was obtained in the range from 5x10(-8) to 1x10(-6) mol/l. The relative standard deviation for 2x10(-7) mol/l HAuCl(4) was 4.2% (n=5). The detection limit was 4x10(-9) mol/l. The accuracy of the method was verified by the determination of gold in reference materials.

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“…They are too expensive for practical applications. The construction of electrode by incorporating an electroactive substances into a carbon paste matrix until now for the determination of trace amounts of some substances [4,5], as electrochemical sensor for the analysis of biologically important compounds [6] and for electrocatalysis [7,8] has been reported. Some advantages of carbon paste electrode (CPE) over all other solid electrodes are the ease and fast preparation and of obtaining a new reproducible surface, the low residual current, porous surface and low cost of carbon paste.…”

mentioning

confidence: 99%

Acetylferrocene Modified Carbon Paste Electrode; A Sensor for Electrocatalytic Determination of Hydrazine

2008

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The electrocatalytic oxidation of hydrazine at a carbon paste electrode spiked with acetylferrocene as a mediator was studied by cyclic voltammetry, differential pulse voltammetry, and chronoamperometry. In contrast to other ferrocenic compounds, acetylferrocene exhibits a chemical irreversible behavior, but it can act as an effective mediator for electrocatalytic oxidation of hydrazine, too. The heterogeneous electron transfer rate constant between acetylferrocene and the electrode substrate (carbon paste) and the diffusion coefficient of spiked acetylferrocene in silicon oil were estimated to be about 3.45 Â 10 À4 cm s À1 and 4.45 Â 10 À9 cm 2 s À1, respectively. It has been found that under the optimum conditions (pH 7.5) the oxidation of hydrazine occurs at a potential of about 228 mV less positive than that of an unmodified carbon paste electrode. The catalytic oxidation peak current of hydrazine was linearly dependent on its concentration and the obtained linear range was 3.09 Â 10 À5 M -1.03 Â 10 À3 M. The detection limit (2s) has been determined as 2.7 Â 10 À5 M by cyclic voltammetry. Also, the peak current was increased linearly with the concentration of hydrazine in the range of 1 Â 10 À5 M -1 Â 10 À3 M by differential pulse voltammetry with a detection limit of 1 Â 10 À5 M. This catalytic oxidation of hydrazine has been applied as a selective, simple, and precise new method for the determination of hydrazine in water samples.Keywords: Acetylferrocene, Electrocatalysis, Hydrazine, Cyclic voltammetry, Carbon paste electrode DOI: 10.1002/elan.200704187 Hydrazine is a small, difunctional and reactive molecule with good reducing capabilities and can enter into diverse reactions in numerous applications. Hydrazine is used for water treatment, agriculture, pharmaceuticals chemical blowing agents and a wide variety of other applications. The electroanalytical techniques have been shown to provide a selective and sensitive approach, based on electrooxidation of hydrazine. The direct oxidation of hydrazine at bare electrode is not suited for analytical application due to slow electrode kinetics and high overpotentials required for redox reactions of hydrazine on many electrodes. For this reason, redox mediators have been widely used in order to decrease the overpotential and increasing the electron transfer kinetics. Different electron transfer mediators such as, metal phthalocyanine [1, 2], tetra-aza-annulenes [1], cobaltpentacyanonitrosyl ferrate [3] have been used for determination of hydrazine.Although metals such as Pt, Au and Ag are very active in anodic oxidation of hydrazine. They are too expensive for practical applications. The construction of electrode by incorporating an electroactive substances into a carbon paste matrix until now for the determination of trace amounts of some substances [4,5], as electrochemical sensor for the analysis of biologically important compounds [6] and for electrocatalysis [7,8] has been reported. Some advantages of carbon paste electrode (CPE) over all other s...

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Voltammetric determination of gold using a carbon paste electrode modified with thiobenzanilide

Cited by 28 publications

References 9 publications

Electrocatalytic Characteristics of a 1-[4-(Ferrocenyl ethynyl)phenyl]-1-ethanone Modified Carbon-Paste Electrode in the Oxidation of Ascorbic Acid

Electrocatalytic Characteristics of a 1-[4-(Ferrocenyl ethynyl)phenyl]-1-ethanone Modified Carbon-Paste Electrode in the Oxidation of Ascorbic Acid

Selective method for the determination of gold by anodic stripping voltammetry

Acetylferrocene Modified Carbon Paste Electrode; A Sensor for Electrocatalytic Determination of Hydrazine

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