scholarly journals Online Coupling of Lab-on-Valve Format to Amperometry Based on Polyvinylpyrrolidone-Doped Carbon Paste Electrode and Its Application to the Analysis of Morin

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yang Wang ◽  
Guojun Yao ◽  
Jie Tang ◽  
Chun Yang ◽  
Qin Xu ◽  
...  

The potential capabilities and analytical performance of lab-on-valve (LOV) manifold as a front end to amperometry have been explored for the on-line determination of morin. Meanwhile, the electrochemical behaviors of morin were investigated based on polyvinylpyrrolidone- (PVP-) doped carbon paste electrode (CPE), which found that PVP can significantly improve its oxidation peak current. The excellent amperometric current response was achieved when the potential difference (ΔE) of 0.6 V was implemented in pH 6.5 phosphate buffer solution (PBS) that served as the supporting electrolyte. A well-defined oxidation peak has been obtained in studies using PVP as a modifier of CPE based on the oxidation of morin. The present work introduces the LOV technique as a useful tool for amperometric measurement, documents advantages of using programmable flow, and outlines means for miniaturization of assays on the basis of PVP modified CPE. The proposed method was applied successfully to the determination of morin in real samples, and the spiked recoveries were satisfactory.

2018 ◽  
Vol 10 (11) ◽  
pp. 1362-1371 ◽  
Author(s):  
Mallappa Mahanthappa ◽  
Nagaraju Kottam ◽  
Shivaraj Yellappa

The simultaneous electroanalysis of acetaminophen (AC), guanine (G) and adenine (A) was successfully achieved on the zinc sulphide nanoparticles-modified carbon paste electrode (ZnS NPs/CPE) in phosphate buffer solution (PBS).


2019 ◽  
Vol 14 (4) ◽  
pp. 216-223 ◽  
Author(s):  
Girish Tigari ◽  
J.G. Manjunatha ◽  
D.K. Ravishankar ◽  
G. Siddaraju

An electrogenerated Polyarginine modified carbon paste electrode (PAMCPE) was fabricated through a simple electropolymerization procedure. The devised electrode was characterized by cyclic voltammetry (CV) and Field Emission Scanning Electron Microscopy (FESEM). This electrode was utilized for electrocatalytic estimation of Riboflavin (RF) and its instantaneous resolution with ascorbic acid (AA) and folic acid (FA) in phosphate buffer solution (PBS) of pH 6.0 by differential pulse voltammetry (DPV). It was observed to be a very responsive electrode for the electrochemical detection and quantification of RF. It was revealed that PAMCPE generates higher current response towards RF contrast to the bare carbon paste electrode (BCPE). Under optimized condition, the RF oxidation current values were linearly reliant on the RF concentration increment with a limit of detection (LOD) of 9.3·10-8 M using DPV. The stable PAMCPE was effectively applied for estimation of RF in B-complex pill and complex human blood serum samples.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
A. B. Teradale ◽  
S. D. Lamani ◽  
B. E. Kumara Swamy ◽  
P. S. Ganesh ◽  
S. N. Das

A polymeric thin film modified electrode, that is, poly(niacinamide) modified carbon paste electrode (MCPE), was developed for the electrochemical determination of catechol (CC) by using cyclic voltammetric technique. Compared to bare carbon paste electrode (BCPE), the poly(niacinamide) MCPE shows good electrocatalytic activity towards the oxidation of catechol in phosphate buffer solution (PBS) of physiological pH 7.4. All experimental parameters were optimized. Poly(niacinamide) modified carbon paste electrode gave a linear response between concentration of CC and its anodic peak current in the range within 20.6–229.0 μM. The limit of detection (3S/M) and limit of quantification (10S/M) were 1.497 μM and 4.99 μM, respectively. From the study of scan rate variation, the electrode process was found to be adsorption-controlled. The involvement of protons and electrons in the oxidation of CC was found to be equal. The probable electropolymerisation mechanism of niacinamide was proposed. Finally, this method can be used in development of a sensor for sensitive determination of CC.


2018 ◽  
Vol 5 (12) ◽  
pp. 181264 ◽  
Author(s):  
Q. Zhou ◽  
H. Y. Zhai ◽  
Y. F. Pan

A chemically modified carbon paste electrode (CPE) was designed by mixing graphite and multi-walled carbon nanotubes (MWCNT). The electrochemical behaviour was studied, and the determination method of phenylephrine hydrochloride (PHE) on this sensor was established. According to the results, the optimal ratio of MWCNTs was approximately 12.5% (w/w). MWCNT-modified carbon paste electrodes (MWCNT-CPEs) showed high electrochemical activity for PHE, producing a sharp oxidation peak current ( I p ) at approximately +0.816 V versus a saturated calomel electrode (SCE) reference electrode in phosphate buffer solution (PBS, pH 6.45), and the I p increased by approximately two times compared to that of the bare CPE. The anodic I p was linearly related with 5.0 × 10 −6 –7.5 × 10 −4 mol l −1 PHE, with a detection limit of 3.7 × 10 −7 mol l −1 . Furthermore, MWCNT-CPEs were successfully applied to the determination of PHE in injection, eye drop and nasal spray liquid samples as a simple, rapid and low-cost method.


Surfaces ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 191-204
Author(s):  
Edwin S. D’Souza ◽  
Jamballi G. Manjunatha ◽  
Chenthattil Raril ◽  
Girish Tigari ◽  
Huligerepura J. Arpitha ◽  
...  

A modest, efficient, and sensitive chemically modified electrode was fabricated for sensing curcumin (CRC) through an electrochemically polymerized titan yellow (TY) modified carbon paste electrode (PTYMCPE) in phosphate buffer solution (pH 7.0). Cyclic voltammetry (CV) linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) approaches were used for CRC detection. PTYMCPE interaction with CRC suggests that the electrode exhibits admirable electrochemical response as compared to bare carbon paste electrode (BCPE). Under the optimized circumstances, a linear response of the electrode was observed for CRC in the concentration range 2 × 10−6 M to 10 × 10−6 M with a limit of detection (LOD) of 10.94 × 10−7 M. Moreover, the effort explains that the PTYMCPE electrode has a hopeful approach for the electrochemical resolution of biologically significant compounds. Additionally, the proposed electrode has demonstrated many advantages such as easy preparation, elevated sensitivity, stability, and enhanced catalytic activity, and can be successfully applied in real sample analysis.


RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 52058-52066 ◽  
Author(s):  
Seyed Naser Azizi ◽  
Shahram Ghasemi ◽  
Mehrnaz Mikhchian

A new amperometric sensor is prepared based on a Ag doped NaA nanozeolite modified carbon paste electrode (Ag/ACPE) in order to detect hydrogen peroxide (H2O2) in phosphate buffer solution (PBS, pH 7.0).


2015 ◽  
Vol 7 (2) ◽  
pp. 27 ◽  
Author(s):  
Francis Tchieno ◽  
Ignas Tonle ◽  
Evangeline Njanja ◽  
Emmanuel Ngameni

We report a simple, sensitive and low-cost electrochemical procedure for the quantification of quercetin (QCT), a flavonoid and an antioxidant, based on 1-ethylpyridinium bromide modified carbon paste electrode. A 1-ethylpyridinium bromide/carbon paste composite electrode was used. The cyclic voltammogram of QCT showed two oxidation peaks at +0.575 V (vs Ag/AgCl/3M KCl) and +0.865 V (vs Ag/AgCl/3M KCl), and a reduction peak at +0.371 V (vs Ag/AgCl/3M KCl) in HCl/KCl solution at pH 1. Differential pulse voltammetry (DPV) analysis in HCl/KCl at pH 1 showed three well-defined oxidation peaks while a single peak was recorded in phosphate buffer at pH 3. The peak currents of QCT significantly increased at the 1-ethylpyridinium bromide modified electrode in comparison with those recorded at the bare carbon paste electrode. This allowed the use of adsorptive stripping voltammetry to develop a simple and sensitive electroanalytical method for the determination of QCT. Key experimental parameters such as pH of the supporting electrolyte, the preconcentration time, the electrolysis potential, electrode composition, QCT concentration and interferents were investigated. The current response was found to be directly proportional to the concentration of QCT in the range from 2.48 x 10-7 M to 7.43 x 10-6 M, leading to a detection limit of 4.48 x 10-8 M. The developed analytical method was successfully applied to the determination of QCT in human urine samples.


2021 ◽  
Vol 19 (1) ◽  
pp. 875-883
Author(s):  
Nevila Broli ◽  
Majlinda Vasjari ◽  
Loreta Vallja ◽  
Sonila Duka ◽  
Alma Shehu ◽  
...  

Abstract In this study, a simple voltammetric method was reported for independent determination of propranolol (PROP) and atenolol (ATN) in pharmaceutical tablets using carbon paste electrode modified with natural Ilmenite (CPE-I). The analytical performance of the modified sensor was evaluated using the square wave voltammetry and cyclic voltammetry for determination of both β(beta) blockers in 0.1 mol L−1 of sulfuric acid solution (H2SO4). The signal obtained with modified carbon paste electrode in 0.1 mol L−1 of H2SO4 showed a good electrocatalytic activity toward the oxidations of PROP and ATN compared with the bare one. The enhanced oxidation peak current response can be attributed to the catalytic effect of the ilmenite nanomaterial incorporated into the carbon paste electrode. Under optimal condition, good linear calibration curves were obtained ranging from 0.20 to 8.9 mmol L−1 for PROP and 2.0 to 9.9 µmol L−1 for ATN, with detection limits of 80 and 0.31 µmol L−1, respectively. The CPE-I sensor had good repeatability and reproducibility (RSD ≤ 3.2%) and high sensitivity for the detection of both ATN and PROP. The proposed sensor was applied for detection of these drugs in pharmaceutical tablets. The obtained results indicate that the voltammetric CPE-I sensor could be an alternative method for the routine quality control of the β blockers in complex matrices.


Author(s):  
Peyman Mohammadzadeh Jahani

The electrochemical sensor was fabricated for the simultaneous determination of levodopa and cabergoline using carbon paste electrode (CPE) modified with graphene quantum dots (GQD), 2-chlorobenzoyl ferrocene (2CBF) and ionic liquid (IL). Then, the electrochemical behavior of levodopa alone and simultaneously with cabergoline at the surface of GQDs/2CBF/IL/CPE was investigated in phosphate buffer solution (PBS). Under optimal PBS, pH=7 condition, oxidation peak current has been found proportional to levodopa concentration in the range between 0.07 μM and 500.0 μM, with the limit of detection (LOD) of 0.02 μM (S/N=3). Outputs showed that at GQDs/2CBF/IL/CPE surface, the levodopa and cabergoline oxidation peaks are separated by the potential difference of 200 mV. In addition, it was found that this modified electrode possesses acceptable sensitivity, selectivity, stability and repeatability. All these properties were sufficient to allow simultaneous detection of levodopa and cabergoline in real samples at the surface of GQDs/2CBF/IL/CPE. This was supported by the successful application of this electro­chemical sensor electrode for the determination of levodopa and cabergoline in urine, serum, and cabergoline tablets.


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