scholarly journals Simultaneous Quantification of Antioxidants Paraxanthine and Caffeine in Human Saliva by Electrochemical Sensing for CYP1A2 Phenotyping

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Rozalia-Maria Anastasiadi ◽  
Federico Berti ◽  
Silvia Colomban ◽  
Claudio Tavagnacco ◽  
Luciano Navarini ◽  
...  
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Human Saliva ◽  
The Body ◽  
Electrochemical Sensing ◽  
Molar Ratio ◽  
Small Scale ◽  
Simultaneous Quantification ◽  
Relative Standard ◽  
Pulse Voltammetry

The enzyme CYP1A2 is responsible for the metabolism of numerous antioxidants in the body, including caffeine, which is transformed into paraxanthine, its main primary metabolite. Both molecules are known for their antioxidant and pro-oxidant characteristics, and the paraxanthine-to-caffeine molar ratio is a widely accepted metric for CYP1A2 phenotyping, to optimize dose–response effects in individual patients. We developed a simple, cheap and fast electrochemical based method for the simultaneous quantification of paraxanthine and caffeine in human saliva, by differential pulse voltammetry, using an anodically pretreated glassy carbon electrode. Cyclic voltammetry experiments revealed for the first time that the oxidation of paraxanthine is diffusion controlled with an irreversible peak at ca. +1.24 V (vs. Ag/AgCl) in a 0.1 M H2SO4 solution, and that the mechanism occurs via the transfer of two electrons and two protons. The simultaneous quantification of paraxanthine and caffeine was demonstrated in 0.1 M H2SO4 and spiked human saliva samples. In the latter case, limits of detection of 2.89 μM for paraxanthine and 5.80 μM for caffeine were obtained, respectively. The sensor is reliable, providing a relative standard deviation within 7% (n = 6). Potential applicability of the sensing platform was demonstrated by running a small scale trial on five healthy volunteers, with simultaneous quantification by differential pulse voltammetry (DPV) of paraxanthine and caffeine in saliva samples collected at 1, 3 and 6 h postdose administration. The results were validated by ultra-high pressure liquid chromatography and shown to have a high correlation factor (r = 0.994).

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.

scholarly journals Electrochemical and analytical performance of boron-doped diamond electrode for determination of ascorbic acid

2017 ◽  
Vol 10 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Ivana Sálusová ◽  
Kristína Cinková ◽  
Barbora Brtková ◽  
Marian Vojs ◽  
Marián Marton ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Analytical Performance ◽  
Current Response ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Relative Standard ◽  
Pulse Voltammetry

Abstract The electrochemical behavior and determination of ascorbic acid (AA) was investigated at a bare boron-doped diamond (BDD) electrode using cyclic and differential pulse voltammetry. The influence of pH of supporting electrolyte and scan rate on the current response of analyte was examined to select the suitable experimental conditions. It was found that AA provided one well-shaped irreversible and diffusioncontrolled oxidation peak at +0.87 V vs. Ag/AgCl in Britton-Robinson buffer pH 4.0. Applying differential pulse voltammetry, the peak current of AA was linearly proportional to its concentration from 5 × 10-6 to 2 × 10-4 mol L-1 (R2 = 0.999), with the limit of detection of 1.1 × 10-6 mol L-1 and the good repeatability (relative standard deviation of 2.3 %). The developed electroanalytical protocol was successfully applied to determine the content of AA in commercial pharmaceutical preparations, based on the standard additions method, with the obtained recovery of 122 %. The accomplished analytical performance indicates that BDD electrodes are promising electrochemical sensors for pharmaceutical analysis.

scholarly journals Promotion Effect of Palladium on BiVO4 Sensing Material for Epinephrine Detection

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1083
Author(s):  
Hsiang-Ning Luk ◽  
Tsong-Yung Chou ◽  
Bai-Hao Huang ◽  
Yu-Syuan Lin ◽  
Hui Li ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Differential Pulse Voltammetry ◽  
Detection System ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
X Ray Diffraction ◽  
Sensing Material ◽  
Transmission Electron ◽  
Pulse Voltammetry ◽  
Epinephrine Concentration

In this study, the Pd/BiVO4 composite was prepared by hydrothermal method as an electrochemical sensing material for epinephrine. X-ray diffraction, scanning electron microscopy, and a transmission electron microscope were used to characterize the samples. In the electrochemical detection system, cyclic voltammetry and differential pulse voltammetry were applied to measure the concentration of the epinephrine solution (0.9–27.5 µM) with the Pd/BiVO4-coated glassy carbon electrode. As a result, the oxidation peak current of Pd/BiVO4/GCE demonstrated good linearity with the epinephrine concentration. The detection limit of the epinephrine concentration by cyclic voltammetry and differential pulse voltammetry were 0.262 µM and 0.154 µM, respectively. Additionally, the proposed sensing material exhibited good reproducibility, stability, and selectivity. A plausible sensing mechanism was proposed.

scholarly journals Simultaneous Quantification of Antipsychotic and Antiepileptic Drugs and Their Metabolites in Human Saliva Using UHPLC-DAD

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2953 ◽  
Author(s):  
Dziurkowska ◽  
Wesolowski
Keyword(s):  
Chromatographic Analysis ◽  
Internal Standard ◽  
Human Saliva ◽  
The Body ◽  
Array Detector ◽  
Diode Array ◽  
Diode Array Detector ◽  
Simultaneous Quantification ◽  
Relative Standard ◽  
Active Substances

Neuroleptics and antiepileptics are excreted in saliva, which can, therefore, be very useful in determining their concentration in the body. This study presents a method developed to simultaneously identify five neuroleptics—olanzapine, quetiapine, risperidone, aripiprazole, and clozapine—and the antiepileptic carbamazepine together with their metabolites: N-demethyl olanzapine, norquetiapine, 9-OH-risperidone, dehydroaripiprazole, N-desmethylclozapine, and carbamazepine-10,11 epoxide. Chlordiazepoxide was used as the internal standard. Strata-X-C columns were used for isolation of the compounds. Chromatographic analysis was carried out using UHPLC with a diode array detector (DAD). A mixture of acetonitrile and water with the addition of formic acid and 0.1% triethylamine was used as the mobile phase. The developed method was validated by determining the linearity for all analytes in the range 10–1000 ng/mL and the value of R2 > 0.99. Intra- and inter-day precision were also determined, and the relative standard deviation (RSD) value in both cases did not exceed 15%. To determine the usefulness of the developed method, saliva samples were collected from 40 people of both sexes treated with the tested active substances both in monotherapy and in polypragmasy. In all cases, the active substances tested were identified.

Investigations On The Binding Of Mercury Ions To Albumins Employing Differential Pulse Voltammetry

2003 ◽  
Vol 10 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Clarissa Pires de Castro ◽  
Jurandir SouzaDe ◽  
Carlos Bloch Jr
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Mercury Ions ◽  
Pulse Voltammetry

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The voltammetric determination of 4-nitrobiphenyl

1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Working Electrode ◽  
Pulse Voltammetry ◽  
Unstirred Solution

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

scholarly journals An efficient electrochemical sensing of hazardous catechol and hydroquinone at direct green 6 decorated carbon paste electrode

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
K. Chetankumar ◽  
B. E. Kumara Swamy ◽  
S. C. Sharma ◽  
S. A. Hariprasad
Keyword(s):  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Tap Water ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Two Peaks ◽  
Paste Electrode ◽  
Scanning Electron

AbstractIn this proposed work, direct green 6 (DG6) decorated carbon paste electrode (CPE) was fabricated for the efficient simultaneous and individual sensing of catechol (CA) and hydroquinone (HY). Electrochemical deeds of the CA and HY were carried out by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at poly-DG6-modfied carbon paste electrode (Po-DG6-MCPE). Using scanning electron microscopy (SEM) studied the surface property of unmodified CPE (UCPE) and Po-DG6-MCPE. The decorated sensor displayed admirable electrocatalytic performance with fine stability, reproducibility, selectivity, low limit of detection (LLOD) for HY (0.11 μM) and CC (0.09 μM) and sensor process was originated to be adsorption-controlled phenomena. The Po-DG6-MCPE sensor exhibits well separated two peaks for HY and CA in CV and DPV analysis with potential difference of 0.098 V. Subsequently, the sensor was practically applied for the analysis in tap water and it consistent in-between for CA 93.25–100.16% and for HY 97.25–99.87% respectively.

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