scholarly journals Cyclic Voltammetric Investigation of Caffeine at Anthraquinone Modified Carbon Paste Electrode

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yemane Tadesse ◽  
Abraha Tadese ◽  
R. C. Saini ◽  
Rishi Pal
Keyword(s):  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Low Cost ◽  
Modified Carbon Paste Electrode ◽  
Good Recovery ◽  
Carbon Paste ◽  
Cyclic Voltammetric ◽  
Anodic Peak Current ◽  
Paste Electrode

Electrochemical methods have been widely used for the determination of electroactive compounds due to their simplicity, sensitivity, stability, and low cost. A carbon paste electrode was modified with anthraquinone. Cyclic voltammetry (CV) was employed to study the properties of the modified electrode toward the oxidation of caffeine (CAF). Compared to the unmodified electrode, the AQMCPE showed excellent catalytic activity for the oxidation of caffeine. AQMCPE was used to determine CAF in drug samples electrochemically. SWV was used to plot the calibration curve and there was a good linear relationship between anodic peak current and CAF concentration in the range2.0×10-6-8.0×10–4 M, with the correlation coefficient of 0.998 and a detection limit of1.43×10-7 M. The application of the modified electrode for the determination of CAF in pharmaceutical formulation showed good recovery with reproducible results.

scholarly journals Electrochemical Determination of Dopamine and Uric Acid Using Poly(proline) Modified Carbon Paste Electrode: A Cyclic Voltammetric Study

2021 ◽  
Vol 15 (2) ◽  
pp. 153-160
Author(s):  
Edwin S. D’ Souza ◽  
◽  
Jamballi G. Manjunatha ◽  
Chenthattil Raril ◽  
◽  
...  
Keyword(s):  
Uric Acid ◽  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Oxidation Potential ◽  
Modified Carbon Paste Electrode ◽  
Current Response ◽  
Carbon Paste ◽  
Cyclic Voltammetric ◽  
Paste Electrode

A cyclic voltammetric technique was used for electropolymerisation of proline on the surface of carbon paste electrode and for individual and concurrent determination of dopamine (DA) and uric acid (UA). The surface morphology of the developed electrode was studied by using field emission scanning electron microscopy. The modified electrode showed a high current response towards DA as compared to the bare electrode. The developed modified electrode shows good catalytic activity with a different oxidation potential of DA and UA. The electrode process was found to be adsorption controlled. The developed method shows very good stability and reproducibility. Under the optimized conditions, the concentration range is (1‒2)∙10-4 M and the observed detection limit was 4.7∙10-6 M. The developed sensor was applied for the determination of DA in the real sample with a good recovery.

Simultaneous Determination of L-Tyrosine and Caffeine Based on Their Electrocatalytic Oxidation at a 4-tert-butylcalix[6] arene-Modified Carbon Paste Electrode

2013 ◽  
Vol 96 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Ashwini K Srivastava ◽  
Reena R Gaichore
Keyword(s):  
Simultaneous Determination ◽  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Simultaneous Detection ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Paste Electrode

Abstract Simultaneous determination of L-tyrosine and caffeine was performed at a carbon paste electrode modified with 4-tert-butylcalix[6]arene and in situ Ni2+ ions. Surface characterization of the electrode was carried out by means of scanning electron microscopy. Electrochemical impedance diagnosis revealed that oxidation of both molecules is kinetically facile on the modified electrode. The electrochemical behavior of both molecules was studied using cyclic voltammetry, and further quantified using differential pulse voltammetry (DPV). The results revealed a high sensitivity for their simultaneous detection. DPV allowed simultaneous detection of L-tyrosine and caffeine in the range of 10–6 to 10–3 M, with LODs of 2.19 × 10–7 and 4.03 × 10–7 M, respectively. The modified electrode was used for individual determination of L-tyrosine and caffeine in various pharmaceutical formulations and simultaneous monitoring in human body fluids.

scholarly journals Ascorbic Acid Determination Based on Electrocatalytic Behavior of Metal-Organic Framework MIL-101-(Cr) at Modified Carbon-Paste Electrode

2019 ◽  
Vol 102 (2) ◽  
pp. 625-632 ◽  
Author(s):  
Javad Tashkhourian ◽  
Hamed Valizadeh ◽  
Abdolkarim Abbaspour
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Wide Range ◽  
Metal Organic ◽  
Paste Electrode

Abstract Background: Metal-organic frameworks (MOFs) are classified as microporous materials. They have large surface areas, low framework densities, accessible cages, and tunnels with modifiable pores. Objective: The MOF MIL-101(Cr) with a large pore volume was synthesized hydrothermally and used in the electrochemical reactions as an electrocatalyst for the determination of ascorbic acid (AA). The synthesized MOF was characterized by scanning electron microscopy and X-ray powder diffraction. Methods: The electrocatalytic behavior of a carbon-paste electrode modified with MIL-101(Cr) was studied through electro-oxidation of AA by cyclic voltammetry and square wave voltammetry. The conventional three-electrode cell system, consisting of Ag/AgCl (3 M KCl) as thereference, platinum wire as the counter electrode, and modified carbon paste as the working electrode,was used in the experiment. Results: Under optimized experimental conditions, the electrode revealed a linear relationship between the oxidation peak current and concentration of AA over a wide range from 0.01 to 10 mM with the LOD of 0.006 mM (3 Sb/m). The results showed that 100-fold ofNa+, K+, Mg2+, Ca2+, Cl−, SO42−, sorbitol, sucrose, fructose, citric acid, 40-fold of NO3−, glucose, sucrose, urea, and 10-fold of uric acid had no significant interference. The method was adapted for the determination of the concentration of AA present in two real samples (vitamin C tablet and vitamin C effervescent tablet) with recovery of 97.0 and 96.0%, respectively. Conclusions: A simple, sensitive and reliable modified electrode has been established and applied for the determination of AA. Highlights: The modified electrode represented a good performance in the analysis of the real sample.

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