Comparative study of the voltammetric behaviour of guanine at carbon paste and glassy carbon electrodes and its determination in purine mixtures by differential-pulse voltammetry

The Analyst ◽  
1992 ◽  
Vol 117 (10) ◽  
pp. 1613 ◽  
Author(s):  
Markas A. T. Gilmartin ◽  
John P. Hart
Keyword(s):  
Comparative Study ◽  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Carbon Electrodes ◽  
Carbon Paste ◽  
Glassy Carbon Electrodes ◽  
Pulse Voltammetry

Ultrasensitive Electrochemical Determination of Phosphate in water by Hydrophilic TiO2 modified Glassy Carbon Electrodes

2021 ◽  
Author(s):  
Yan Jin ◽  
Tong QI ◽  
Yuqing Ge ◽  
Jin Chen ◽  
Li juan Liang ◽  
...  
Keyword(s):  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Time Differential ◽  
Pulse Voltammetry ◽  
First Time

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by hydrophilic TiO2 modified glassy carbon electrodes for the first time. Differential pulse voltammetry (DPV) method is proposed...

scholarly journals Electroanalytical Characterisation of Dopa Decarboxylase Inhibitors Carbidopa and Benserazide on Multiwalled Carbon Nanotube and Poly(Nile blue A) Modified Glassy Carbon Electrodes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Dilek Kul ◽  
Christopher M. A. Brett
Keyword(s):  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Nile Blue ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Carbon Electrodes ◽  
Potential Cycling ◽  
Multiwalled Carbon ◽  
Glassy Carbon Electrodes ◽  
Pulse Voltammetry

Modified glassy carbon electrodes have been made by deposition of functionalised multiwalled carbon nanotubes (MWCNTs) followed by formation of poly(Nile blue) (PNB) films by electropolymerisation, using potential cycling in 0.1 M phosphate buffer solution (PBS) at pH 6.0. The electrochemical oxidation of carbidopa (CD) and benserazide (BS) on these MWCNTs/PNB-modified electrodes was investigated using cyclic and differential pulse voltammetry in 0.1 M PBS at different values of pH between 5.0 and 8.0; both CD and BS gave one diffusion-controlled irreversible oxidation peak in cyclic voltammetry. Analytical characterisation of CD and BS was carried out in 0.1 M PBS, pH 5.0. Peak currents in differential pulse voltammetry were linear over the concentration range of1×10−5to1×10−4 M for CD and4×10−6to4×10−5 M for BS. The repeatability, precision, and accuracy of the method were also investigated. Higher sensitivities and lower detection limits, of 1.17 μM for CD and 0.50 μM for BS, were obtained with this new modified electrode compared with previous studies reported in the literature.

Nafion-coated mercury-coated glassy carbon electrodes for metals analysis and speciation

1987 ◽  
Vol 65 (5) ◽  
pp. 1133-1138 ◽  
Author(s):  
Robert D. Guy ◽  
Sarath Namaratne
Keyword(s):  
Ionic Strength ◽  
Ion Exchange ◽  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Metal Ion ◽  
Differential Pulse ◽  
Carbon Electrodes ◽  
Linear Calibration ◽  
Glassy Carbon Electrodes ◽  
Pulse Voltammetry

The properties of mercury-coated glassy carbon electrodes coated with a thin membrane of Nation 117 were studied to evaluate the potential analytical applications in metal ion analysis. The Nation membrane was found to contain two types of binding sites — a strong site that bound metal ions in a nonelectroactive form and cation exchange sites that were useful for preconcentrations prior to differential pulse voltammetry. The exchange constants for the weak sites ranged from 0.413 for copper to 12.5 for methyl viologen. The differential pulse currents were increased by a factor of 75 to 100 and a linear calibration curve was observed from about 25 n M to 1000 n M for copper, lead, cadmium, and zinc. The ion exchange reaction is very sensitive to ionic strength and significant enrichments occur only in solutions of ionic strength below 0.10. The Nafion-coated glassy carbon electrode in a flow cell can be used to determine the free copper ion concentration in samples by a combination of ion exchange and differential pulse voltammetry. The flow-through system required about 15 mL of sample solution and an analysis time of about 10 min. The ion exchange measurement gave a linear calibration from 40 n M to 10 μ M for free copper.

Determination of chloramphenicol by differential pulse voltammetry at carbon paste electrodes – The use of sodium sulfite for removal of oxygen from electrode surface

2011 ◽  
Vol 76 (5) ◽  
pp. 383-397 ◽  
Author(s):  
Ferenc T. Pastor ◽  
Hana Dejmková ◽  
Jiří Zima ◽  
Jiří Barek
Keyword(s):  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Sodium Sulfite ◽  
Differential Pulse ◽  
Optimal Conditions ◽  
Carbon Paste ◽  
Tricresyl Phosphate ◽  
Carbon Paste Electrodes ◽  
Pulse Voltammetry

The possibility of determination of chloramphenicol by differential pulse voltammetry at four different carbon paste electrodes, in the full pH range (2–12) of Britton–Robinson (BR) buffer was investigated. Electrodes were prepared by mixing spectroscopic graphite powder or glassy carbon microbeads with mineral oil (Nujol) or tricresyl phosphate. Under optimal conditions (BR buffer pH 12, the electrode prepared from glassy carbon microbeads and tricresyl phosphate), linear calibration graph was obtained only in 10–5 M chloramphenicol concentration range. Determination of lower concentrations of chloramphenicol was complicated by irreproducible peak of oxygen from the carbon paste which overlapped with peak of chloramphenicol. Addition of sodium sulfite removed the oxygen peak without influence on the peak of chloramphenicol. Under optimal conditions (electrode paste made from glassy carbon microbeads, BR buffer pH 10 and 0.5 M sodium sulfite), straight calibration line was obtained in the 10–6 and 10–5 M chloramphenicol concentration range. Limit of determination was 5 × 10–7 mol/l.

Electrochemical study of glimepiride and its complexation with β-cyclodextrin

2010 ◽  
Vol 76 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Abd-Elgawad M. Radi ◽  
Shimaa H. Eissa
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Phosphate Buffer ◽  
Differential Pulse ◽  
Uv Spectrophotometry ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Ph Range ◽  
Tablet Dosage

The electrochemical behavior of a hypoglycemic drug, glimepiride (GM), was studied at glassy carbon (GCE) and carbon paste (CPE) electrodes in phosphate buffer over the pH range of 2.7–11.7 using cyclic and differential pulse voltammetry. Oxidation of the drug was shown to be an irreversible and diffusion-controlled process. Using differential pulse voltammetry (DPV), the drug yielded a well-defined voltammetric peak in phosphate buffer pH 6.4 at +1.16 V and pH 7.0 at +1.07 V (vs Ag|AgCl) on glassy carbon and carbon paste electrodes, respectively. This process could be used to determine glimepiride concentrations in the range from 1.0 × 10–5 to 3.2 × 10–5 mol l–1 with a detection limit of 2.0 × 10–6 mol l–1 in case of the glassy carbon electrode and in the range of 2.0 × 10–6 to 1.5 × 10–5 mol l–1 with a detection limit of 7.5 × 10–7 mol l–1 in case of the carbon paste electrode. The method was successfully applied to the determination of the drug in a tablet dosage form. Next, the formation of an inclusion complex of glimepiride with β-cyclodextrin (β-CD) in phosphate buffer (pH 7.0):methanol (90:10 (v/v)) has been investigated by differential pulse voltammetry as well as UV spectrophotometry and its stability constant was determined by both methods to be 202.0 and 197.9 l mol–1, respectively.

Electrocatalytic Reduction of Nitrite at Carbon-Nanotube-Modified Glassy Carbon Electrodes

2011 ◽  
Vol 306-307 ◽  
pp. 1221-1224
Author(s):  
Dan Zi Sun
Keyword(s):  
Carbon Nanotube ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Carbon Electrodes ◽  
Carbon Electrode ◽  
Electrocatalytic Reduction ◽  
Modified Glassy Carbon Electrode ◽  
Electrocatalytic Property ◽  
Glassy Carbon Electrodes ◽  
Pulse Voltammetry

Carbon-nanotube(CNT)-modified glassy carbon electrodes exhibiting strong electrocatalytic response toward nitrite are described. Cyclic voltammetry and differential pulse voltammetry are used to investigate the electrocatalytic property of CNT-modified glassy carbon electrode toward the reduction of nitrite. The modified electrode could be used for nitrite sensing.

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