Voltammetry glassy carbon electrode

LiF-BeFa 500 Linear sweep voltammetry, chronopotentiometry, and voltammetry (glassy carbon electrode) Xi3 + 192 tr 3. 35 S 2 2-... 

The purity of a sample of K3Fe(CN)6 was determined using linear-potential scan hydrodynamic voltammetry at a glassy carbon electrode using the method of external standards. The following data were obtained for a set of calibration standards. 

The D.M.E. can with advantage be replaced by an S.M.D.E. (Section 16.8), and it is possible to use platinum, graphite, or glassy carbon electrodes, in which case the procedure should be termed voltammetry rather than polarography. 

Determined by direct electrochemistry at a glassy carbon electrode (cyclic, differential pulse, or square-wave voltammetry). 

Traore M, Moddo R, Vittori O (1988) Electrochemical behaviour of tellurium and silver teUuride at rotating glassy carbon electrode. Hectrochim Acta 33 991-996 Ngac N, Vittori O, Quarin G (1984) Voltammetrie and chronoamperometric studies of tellurium electrodeposition of glassy carbon and gold electrodes. J Electroanal Chem 167 227-235... 

Cyclic voltammetry, square-wave voltammetry, and controlled potential electrolysis were used to study the electrochemical oxidation behavior of niclosamide at a glassy carbon electrode. The number of electrons transferred, the wave characteristics, the diffusion coefficient and reversibility of the reactions were investigated. Following optimization of voltammetric parameters, pH, and reproducibility, a linear calibration curve over the range 1 x 10 6 to 1 x 10 4 mol/dm3 niclosamide was achieved. The detection limit was found to be 8 x 10 7 mol/dm3. This voltammetric method was applied for the determination of niclosamide in tablets [33]. 

Detection of damage caused to DNA by niclosamide in schistosomiasis was investigated using an electrochemical DNA-biosensor. It showed for the first time clear evidence of interaction of niclosamide with DNA and suggested that niclosamide toxicity can be caused by this interaction, after reductive activation. The electrochemical reduction and oxidation of niclosamide involved the use of cyclic, differential, and square-wave voltammetry, at a glassy carbon electrode. It enabled the detection limit of 8 x 10-7 M [34]. 

Alemu et al. [35] developed a very sensitive and selective procedure for the determination of niclosamide based on square-wave voltammetry at a glassy carbon electrode. Cyclic voltammetry was used to investigate the electrochemical reduction of niclosamide at a glassy carbon electrode. Niclosamide was first irreversibly reduced from N02 to NHOH at —0.659 V in aqueous buffer solution of pH 8.5. Following optimization of the voltammetric parameters, pH and reproducibility, a linear calibration curve over the range 5 x 10 x to 1 x 10-6 mol/dm3 was achieved, with a detection limit of 2.05 x 10-8 mol/dm3 niclosamide. The results of the analysis suggested that the proposed method has promise for the routine determination of niclosamide in the products examined [35]. 

A. Salimi, E. Sharifi, A. Noorbakhsh, and S. Soltanian. Direct voltammetry and electrocatalytic properties of haemoglobin immobilized on a glassy carbon electrode modified with nickel oxide nanoparticles. Electrochem. Commun. 8, 1499-1508 (2005). 

Fogg et al. [ 149] used flow injection voltammetry to reduce nitrite at a glassy carbon electrode in acidic bromide or chloride medium and applied the method to seawater. 

Other techniques that have been used include subtractive differential pulse voltammetry at twin gold electrodes [492], anodic stripping voltammetry using glassy-carbon electrodes [495,496], X-ray fluorescence analysis [493], and neutron activation analysis [494],... 

Aniline, methyl aniline, 1-naphthylamine, and diphenylamine at trace levels were determined using this technique and electrochemical detection. Two electrochemical detectors (a thin-layer, dual glassy-carbon electrode cell and a dual porous electrode system) were compared. The electrochemical behavior of the compounds was investigated using hydrodynamic and cyclic voltammetry. Detection limits of 15 and 1.5nmol/l were achieved using colourimetric and amperometric cells, respectively, when using an in-line preconcentration step. 

The oxidation of hydroxide ion in acetonitrile at copper, silver, gold, and glassy-carbon electrodes has been characterized by cyclic voltammetry. In the absence of bases the metal electrodes are oxidized to their respective cations (Cu+, Ag+, and Au+) at potentials that range from -0.2V vs. SCE for Cu to +1.3 V for Au. At glassy carbon OH is oxidized to 0 - (+0.35 V vs SCE) and then to... 

FIGURE 4.3. Redox and chemical homogeneous catalysis of trans-1,2 dibromocyclohexane. a cyclic voltammetry in DMF of the direct electrochemical reduction at a glassy carbon electrode (top), of redox catalysis by fhiorenone (middle), of chemical catalysis by an iron(I) porphyrin, b catalysis rate constant as a function of the standard potential of the catalyst couple aromatic anion radicals, Fe(I), a Fe(0), Co(I), Ni(I) porphyrins. Adapted from Figures 3 and 4 of reference lb, with permission from the American Chemical Society. 

FIGURE 4.8. Cyclic voltammetry of cobinamide 0.5 mM alone (dashed line) and in the presence of 1.5 mM chloroacetonitrile (solid line) in a 70-30 H20-EtOH + 0.1 M NaCl mixture on a glassy carbon electrode at a scan rate of 0.2 V/s. Adapted from Figure 1 of reference 9, with permission from the American Chemical Society. 

CycUc voltammetry was carried out on the Sycopel Work Station AEW 2, a three electrode assembly glassy carbon electrode as working, graphite rod as counter and anHg-pool as reference electrode were used. The stability and drift of Hg-pool was checked from time to time and found satisfactory. The scan rate was either 50 or 100 mV/s. 

Figure 9. Dependence of Dapp of compound 6 (O, right axis) and compound 7 (, left axis) on the weight fraction of the cross-linker. Obtained by cyclic voltammetry and potential-step chronoamperometry on a 3-mm-diameter glassy carbon electrode under argon 0.1 M NaCl, 20 mM phosphate buffer, pH 7, 37 °C, 20 mV/s. Reprinted with permission from ref 126. Copyright 2003 American Chemical Society.

Reduction potentials for alkyl and benzyl halides measured by cyclic voltammetry at 0.1 or 0.2 V s" with a glassy carbon electrode in dimethylformamide. 

The effectiveness of glassy-carbon electrodes coated with cellulose acetate for adsorptive stripping voltammetry was evaluated to alleviate interference from co-adsorbed species [171]. The carbon electrode was coated using a 5% cellulose acetate solution, with the coating being hydrolyzed with 0.07M potassium hydroxide. Repetitive measurements of 1 pM chlorpromazine in the presence of 20 mg/L albumin resulted in peak currents with residual standards of deviation equal to 1.4 and 1.3%, respectively. 

Fig. 1 Cyclic voltammetry pattern at a glassy carbon electrode (GC Tokai, Japan) with 10 M a-K6P2Wig062 in 1 M HCl supporting electrolyte. Sweep rate 100 mV s electrode surface area ...

The oxidized forms of these two sandwich-type POMs are stable from pH 3 to at least pH 7. Their characterization by cyclic voltammetry revealed the stepwise reduction of the Gu " " centers within the POMs, before Gu" deposition on the glassy carbon electrode surface [115]. Phenomena are described mainly for the P-derivative and are the same for the As-analog. 

Also, sodium montmorillonite-modified carbon paste electrode has been used for the determination of trace concentrations of mercury [80]. Hg + was preconcentrated at the electrode, reduced, and then stripped from the electrode surface in the positive potential scan. At a glassy carbon electrode modified with dithizone, mercury has been determined, applying anodic stripping voltammetry [81]. 

Measured by conventional cyclic voltammetry. A monolayer of 28 (R BuO prepared on water and compressed at 25 mN m, was transferred on a glassy carbon electrode by the Langmuir-Blodgen method. The markers were added as Na4[Fe(CN)J, mcthylviologen dichloride, orp-quinone (1,4-benzoquinone) (1.00 X 10 M concentration in all cases). 

Figure 8.1 Cyclic voltammetry (a) and Osteryoung square wave voltammetry (b) of Cgo (acetonitrile/toluene + 0.1 M ( -Bu)4NPF6), using a glassy carbon electrode (GCE) working and ferrocene/ferrocenium (Fc/Fc +) couple as an internal reference. Reprinted with Permission from Ref. 4. Copyright 1992 American Chemical Society.

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