scholarly journals Voltammetric Determination of Uric Acid in Clinical Serum Samples Using DMF Modified Screen Printed Carbon Electrodes

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Melaku Metto ◽  
Samrawit Eramias ◽  
Bekele Gelagay ◽  
Alemayehu P. Washe
Keyword(s):  
Uric Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Clinical Samples ◽  
Carbon Electrodes ◽  
Current Response ◽  
Serum Samples ◽  
Relative Standard ◽  
Screen Printed

Screen printed carbon electrodes (SPCEs) provide attractive opportunity for sensitive and selective determination target analytes in clinical samples. The aim of the current work was to develop SPCEs based sensor for the determination of uric acid in clinical serum samples. The electrodes were pretreated by soaking in N,N-dimethylformamide for 5 minutes followed by drying in an oven at 100°C for 20 mins. The effect of surface pretreatment was characterized using cyclic voltammetry. The current response of uric acid detection was improved by a factor of 3.5 in differential pulse voltammetric measurement compared to unmodified electrode. Under the optimized conditions, the sensor displayed two dynamic linear ranges 5-100 μM and 100-500 μM with correlation coefficient, R2, values of 0.98782 and 0.97876, respectively. The limit of detection and limit of quantification calculated using the dynamic linear range 5-100 μM were 1.9 x 10−7 M and 6.33 x 10−7 M, respectively. The developed sensor displayed well separated and discerned peaks for UA in presence of the potential interferent (ascorbic acid and citric acid). The electrode was successfully applied for the detection of very low level of UA in clinical serum samples in a phosphate buffer solution (pH = 7). The proposed sensor showed a very high reproducibility and repeatability with the relative standard deviation of 0.9%. In conclusion, a simple and low cost sensor based on SPCEs is developed for sensitive and selective detection of uric acid in clinical samples.

scholarly journals Determination of uric acid in human serum by an enzymatic method using N-methyl-N-(4-aminophenyl)-3-methoxyaniline reagent

2003 ◽  
Vol 68 (8-9) ◽  
pp. 691-698 ◽  
Author(s):  
Milena Jelikic-Stankov ◽  
Predrag Djurdjevic ◽  
Dejan Stankov
Keyword(s):  
Uric Acid ◽  
Human Serum ◽  
Limit Of Detection ◽  
Ascorbate Oxidase ◽  
Acid Oxidation ◽  
Uric Acid Concentration ◽  
Enzymatic Method ◽  
Limit Of Quantification ◽  
Relative Standard

In this work a new enzymatic method for the determination of uric acid in human serum has been developed. The method is based on the oxidative coupling reaction between the N-methyl-N-(4-aminophenyl)-3-methoxyaniline (NCP) reagent and the hydrogen ? donor reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (TOOS), in the system involving three enzymes: uricase, peroxidase and ascorbate oxidase. Using this method uric acid could be determined in concentrations up to 1.428 mmol/L, with a relative standard deviation of up to 1.8 %. The effect of the medium pH and the NCP concentration on the linearity of the chromogen absorbance versus the uric acid concentration curve was investigated. The influence of the uricase activity on the maximum rate of uric acid oxidation was also examined. The use of the NCP reagent demonstrated a more precise and more sensitive determination of the uric acid compared to the determination with 4-aminoantipyrine (4-AA) as the coupling regent. The sensitivity of the method determined from the calibration curve was 0.71 absorbance units per mmol/L of uric acid; the limit of detection was LOD = 0.0035 mmol/L and the limit of quantification was LOQ = 0.015 mmol/L of uric acid.

scholarly journals Carvacrol electrochemical reaction characteristics on screen printed electrode modified with La2O3/Co3O4 nanocomposite

2019 ◽  
Vol 9 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Sayed Zia Mohammadi ◽  
Hadi Beitollahi ◽  
Tahereh Rohani ◽  
Hossein Allahabadi
Keyword(s):  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Co3o4 Nanoparticles ◽  
Electrochemical Characteristics ◽  
Screen Printed Electrode ◽  
Buffer Solution ◽  
Voltammetric Techniques ◽  
Screen Printed

Electrochemical characteristics of carvacrol were investigated on a screen-printed electrode (SPE) modified with La2O3/Co3O4 nanocomposite by using voltammetric techniques, which displayed a well-defined peak for sensitive carvacrol determination in phosphate buffer solution (PBS) at pH 7.0. La2O3/Co3O4 nanoparticles demonstrated suitable catalytic activity for carvacrol determination by differential pulse voltammetry (DPV) technique. Besides, determination of carvacrol in a real samples was recognized in the light of electrochemical findings and a validated voltammetric technique for quantitative analysis of carvacrol in a real formulation was proposed. The DPV peak currents were found to be linear in the concentration range of 10.0 to 800.0 μM. The limit of detection (LOD) was found to be 1.0 μM.

Determination of ascorbic acid in serum samples by screen-printed carbon electrodes modified with gold nanoparticles

Talanta ◽  
2017 ◽  
Vol 174 ◽  
pp. 733-737 ◽  
Author(s):  
M. Asunción Alonso-Lomillo ◽  
Olga Domínguez-Renedo ◽  
Abraham Saldaña-Botín ◽  
M. Julia Arcos-Martínez
Keyword(s):  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Carbon Electrodes ◽  
Serum Samples ◽  
Screen Printed

Enhanced Electrochemical Determination Of Riboflavin In Biological And Pharmaceutical Samples At Poly (Arginine) Modified Carbon Paste Electrode

2019 ◽  
Vol 14 (4) ◽  
pp. 216-223 ◽  
Author(s):  
Girish Tigari ◽  
J.G. Manjunatha ◽  
D.K. Ravishankar ◽  
G. Siddaraju
Keyword(s):  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Modified Carbon Paste Electrode ◽  
Current Response ◽  
Carbon Paste ◽  
Serum Samples ◽  
Buffer Solution ◽  
Paste Electrode

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.

scholarly journals Spectrophotometric and RP-HPLC Methods for Determining Cefotaxime Sodium in Pharmaceutical Preparations

2020 ◽  
Vol 32 (6) ◽  
pp. 1314-1320
Author(s):  
Lamya A. Sarsam ◽  
Salim A. Mohammed ◽  
Sahar A. Fathe
Keyword(s):  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Buffer Solution ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Relative Standard

A rapid, simple and sensitive spectrophotometric and RP-HPLC methods have been developed for the quantitative determination of cefotaxime-Na in both pure and dosage forms. The spectrophotometric method was based on diazotization of cefotaxime-Na and then coupling with 8-hydroxyquinoline in an alkaline medium. The resulting azo dye exhibited maximum absorption at 551 nm with a molar absorptivity of 0.597 × 104 L mol-1 cm-1. Beer′s law was obeyed over the range 10-700 μg/25 mL (i.e. 0.4-28.0 ppm) with an excellent determination coefficient (R2 = 0.9993). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.0194 and 0.3765 μg mL-1, respectively. The recoveries were obtained in the range 97.3-102.5% and the relative standard deviation (RSD) was better than ± 1.56. The HPLC method has been developed for the determination of cefotaxime-Na. The analysis were carried out on a C18 column and a mobile phase composed of acetonitrile and phosphate buffer solution (0.024M KH2PO4 and 0.01M H3PO4) at pH 3.5 in the ratio of 60:40 (v:v), with a flow rate of 1.0 mL min-1 and UV detection at 258 nm. The proposed method showed good linearity (in a range of concentration 1.0-200 μg mL-1. The recovery percent and a relative standard deviations were found in the range 96 to 104.8% and ± 0.017 to ± 0.031%, respectively. Both methods were applied successfully to the assay of cefotaxime-Na in commercial injection preparations.

Simultaneous and selective determination of dopamine and tyrosine in the presence of uric acid with 2D-MoS2 nanosheets modified screen-printed carbon electrodes

FlatChem ◽  
2020 ◽  
Vol 24 ◽  
pp. 100187 ◽  
Author(s):  
Rayhane Zribi ◽  
Ramzi Maalej ◽  
Raymond Gillibert ◽  
Maria G. Donato ◽  
Pietro G. Gucciardi ◽  
...  
Keyword(s):  
Uric Acid ◽  
Carbon Electrodes ◽  
Mos2 Nanosheets ◽  
Selective Determination ◽  
Screen Printed

scholarly journals Voltammetric Determination of Captopril Using Chlorpromazine as a Homogeneous Mediator

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hossein Bahramipur ◽  
Fahimeh Jalali
Keyword(s):  
Electron Transfer ◽  
Limit Of Detection ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Formulations ◽  
Electron Transfer Reaction ◽  
Linear Calibration ◽  
Serum Samples ◽  
Catalytic Rate Constant ◽  
Relative Standard

Chlorpromazine was used as a homogeneous electrocatalyst in the oxidation of captopril. The anodic peak current of chlorpromazine was increased substantially in the presence of low concentrations of captopril (pH 4). Cyclic voltammetry and chronoamperometry were used to study the kinetics of the catalytic electron transfer reaction. The values of electron transfer coefficient () and catalytic rate constant () were estimated to be 0.34 and , respectively. Linear sweep voltammetry was used for the determination of captopril in the presence of chlorpromazine. A linear calibration curve was obtained in the concentration range of captopril of 10.0–300.0 μM, with a limit of detection of 3.65 μM. The relative standard deviation (RSD%) for 5 replicate measurements of captopril (100 μM) was 1.96%. The method was applied to the determination of captopril in pharmaceutical formulations and blood serum samples with satisfactory results.

scholarly journals SIMULTANEOUS DETERMINATION OF DOPAMINE IN THE PRESENCE OF ASCORBIC ACID AND URIC ACID BY ELECTROCHEMICALLY OXIDIZED SCREEN PRINTED CARBON ELECTRODE

2018 ◽  
Vol 55 (5B) ◽  
pp. 78
Author(s):  
Nguyen Xuan Viet
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Electrochemical Technique ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Simple Method ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

This research reported the simple method to determine of dopamine (DA) in the simultaneous presence of ascorbic acid (AA) and uric acid (UA). Three – electrode system manufactured by screen printing method was used due to its disposal and low cost. The screen printed carbon electrode (SPCE) was oxidized by electrochemical technique in acid medium. The capacity of oxidized electrode for selective detection of dopamine was confirmed in a sufficient amount of ascorbic acid and uric acid. The large separated peaks of DA from ascorbic acid and uric acid are observed. The peak separation between UA and DA, DA and AA was 110 mV and 160 mV, respectively. The bare SPCE cannot determine simultaneously AA and DA due to the overlap peaks of AA and DA around 0.2 V vs AgCl/Ag. This sensor also exhibited good sensitivity to DA with limit of detection 100 nM in phosphate buffer solution.

scholarly journals Dendrites Nanostructures of Co3O4 for the Selective Determination of Uric Acid

2021 ◽  
Author(s):  
Ramesh Lal ◽  
Bhajan Lal Bhattia ◽  
Ali M. Alsalme ◽  
Asma A. Al-Othman ◽  
Ayman Nafady ◽  
...  
Keyword(s):  
Composite Material ◽  
Uric Acid ◽  
Limit Of Detection ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Clinical Samples ◽  
Buffer Solution ◽  
Solution Ph ◽  
Dendrite Morphology ◽  
Selective Determination

Abstract The gout is mainly found due to accumulation of uric acid crystals into the joints which produces the inflammatory symptoms. Thus, it is highly demanded to detect uric acid from our body. Herein, we used wet chemical method for the preparation of composite material of cobalt oxide (Co3O4) with hydroxide functionalized multi-walled carbon nanotubes (MWCNTs). The analytical techniques such as scanning electron microscopy (SEM), powder X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and Infra-red spectroscopy (FTIR) were used to characterize the composite material. The Co3O4 exhibits a dendrite morphology and very well chemically coupled with MWCNTs. The elemental analysis confirmed the presence of Co, O and C as main constituent of the composite material. The Co3O4 exhibits a cubic unit cell crystallography in the composite system. The FTIR study has revealed the characteristic bands of Co-O bands in the composite material. The cyclic voltammetry was used to study the electrochemical properties of prepared materials. The composite sample with highest percentage of MWCNTs showed an excellent electrochemical activity towards the oxidation of uric acid in phosphate buffer solution pH 7.3. The enzyme free uric acid sensor possessed a linear range of 0.1 mM to 3 mM with a quantified limit of detection of 0.005 mM. The modified electrode is stable, selective, and very sensitive towards uric acid, therefore it may be used for the monitoring of uric acid from clinical samples. The proposed composite material is low cost, and earth abundant, thus it can be of great interest for energy and biomedical fields.

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