Microelectrodes based on porphyrins for the determination of ascorbic acid in pharmaceutical samples and beverages

2012 ◽  
Vol 16 (07n08) ◽  
pp. 809-816 ◽  
Author(s):  
Raluca-Ioana Stefan-van Staden ◽  
Simona Cornelia Balasoiu ◽  
Jacobus Frederick van Staden ◽  
Gabriel-Lucian Radu
Keyword(s):  
Ascorbic Acid ◽  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Limits Of Detection ◽  
Pharmaceutical Samples ◽  
Pulse Voltammetry ◽  
Fresh Surface ◽  
Diamond Paste

Different porphyrins were used for the design of seven carbon paste and seven diamond paste based microelectrodes, which were employed for the determination of ascorbic acid in pharmaceutical and beverages samples using differential pulse voltammetry (DPV). The limits of detection lie between 1.1 × 10-14 and 5.1 × 10-7 M while the sensitivities were between 3.07 pA/M and 1285.18 A/M. Ascorbic acid was recovered reliable from pharmaceutical and beverages samples in percentages higher than 92.00% and 91.50%, respectively. The surface of the microelectrodes can easily be renewed by simple polishing, obtaining a fresh surface ready for use in a new assay.

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.

scholarly journals Simultaneous Quantification of Four Principal NSAIDs through Voltammetry and Artificial Neural Networks Using a Modified Carbon Paste Electrode in Pharmaceutical Samples

2021 ◽  
Vol 5 (1) ◽  
pp. 3
Author(s):  
Guadalupe Yoselin Aguilar-Lira ◽  
Prisciliano Hernandez ◽  
Giaan Arturo Álvarez-Romero ◽  
Juan Manuel Gutiérrez
Keyword(s):  
Differential Pulse Voltammetry ◽  
Carbon Paste Electrode ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Pharmaceutical Samples ◽  
Simultaneous Quantification ◽  
Drug Concentrations ◽  
Pulse Voltammetry ◽  
Artificial Neural ◽  
Paste Electrode

This work describes the development of a novel and low-cost methodology for the simultaneous quantification of four main nonsteroidal anti-inflammatory drugs (NSAIDs) in pharmaceutical samples using differential pulse voltammetry coupled with an artificial neural network model (ANN). The working electrode used as a detector was a carbon paste electrode (CPE) modified with multi-wall carbon nanotubes (MWCNT-CPE). The specific voltammetric determination of the drugs was performed by cyclic voltammetry (CV). Some characteristic anodic peaks were found at potentials of 0.446, 0.629, 0.883 V related to paracetamol, diclofenac, and aspirin. For naproxen, two anodic peaks were found at 0.888 and 1.14 V and for ibuprofen, an anodic peak was not observed at an optimum pH of 10 in 0.1 mol L−1 Britton–Robinson buffer. Since these drug’s oxidation process turned out to be irreversible and diffusion-controlled, drug quantification was carried out by differential pulse voltammetry (DPV). The Box Behnken design technique’s optimal parameters were: step potential of 5.85 mV, the amplitude of 50 mV, period of 750 ms, and a pulse width of 50 ms. A data pretreatment was carried out using the Discrete Wavelet Transform using the db4 wavelet at the fourth decomposition level applied to the voltammetric records obtained. An ANN was built to interpret the obtained approximation coefficients of voltammograms generated at different drug concentrations to calibrate the system. The ANN model’s architecture is based on a Multilayer Perceptron Network (MLP) that employed a Bayesian regularization training algorithm. The trained MLP achieves significant R values for the test data to simultaneous quantification of the four drugs in the presence of aspirin.

DIFFERENTIAL PULSE VOLTAMMETRY FOR DETERMINATION OF PARACETAMOL AT A PUMICE MIXED CARBON PASTE ELECTRODE

2001 ◽  
Vol 34 (15) ◽  
pp. 2747-2759 ◽  
Author(s):  
Chengyin Wang ◽  
Xiaoya Hu ◽  
Zongzhou Leng ◽  
Gongjun Yang ◽  
Gendi Jin
Keyword(s):  
Differential Pulse Voltammetry ◽  
Carbon Paste Electrode ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Paste Electrode

A graphene/ionic liquid modified selenium-doped carbon paste electrode for determination of copper and antimony

2016 ◽  
Vol 8 (5) ◽  
pp. 1120-1126 ◽  
Author(s):  
Rong Liu ◽  
Cunxi Lei ◽  
Tongsheng Zhong ◽  
Liping Long ◽  
Zhaoyang Wu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Differential Pulse Voltammetry ◽  
Carbon Paste Electrode ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Paste Electrode ◽  
Determination Of Copper

A graphene (GN) and ionic liquid (IL) modified selenium-doped carbon paste electrode (GN/IL/Se/CPE) was established to simultaneously determine trace Cu(ii) and Sb(iii) by differential pulse voltammetry (DPV).

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