Simultaneous Determination of Epinephrine and Tyrosine Using a Glassy Carbon Electrode Amplified with ZnO-Pt/CNTs Nanocomposite

2019 ◽  
Vol 15 (2) ◽  
pp. 166-171 ◽  
Author(s):  
Ali Samadzadeh ◽  
Iran Sheikhshoaie ◽  
Hassan Karimi-Maleh
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Simultaneous Analysis ◽  
Urine Samples ◽  
Carbon Electrode ◽  
Linear Dynamic ◽  
Biological Compounds ◽  
Blood And Urine Samples ◽  
Human Blood And Urine

Background: Simultaneous analysis of epinephrine and tyrosine as two effective and important biological compounds in human blood and urine samples are very important for the investigation of human health. Objective: In this research, a highly effective voltammetric sensor fabricated for simultaneous analysis of epinephrine and tyrosine. The sensor was fabricated by the modification of glassy carbon electrode with ZnO-Pt/CNTs nanocomposite (ZnO-Pt/CNTs/GCE). The synthesized nanocomposite was characterized by SEM method. The ZnO-Pt/CNTs/GCE showed two separated oxidation signals at potential ~220 mV and 700 mV for epinephrine and tyrosine, respectively. Also, we detected linear dynamic ranges 0.5-250.0 µM and 1.0-220 µM with a limit of detections 0.1 µM and 0.5 µM for the determination of epinephrine and tyrosine, respectively. The ZnO-Pt/CNTs/GCE was used for the determination of epinephrine and tyrosine in blood serum and human urine samples.

scholarly journals Voltammetric determination of some alkaloids and other compounds in pharmaceuticals and urine using an electrochemically activated glassy carbon electrode

2011 ◽  
Vol 9 (4) ◽  
pp. 688-700 ◽  
Author(s):  
Anuţa Câmpean ◽  
Mihaela Tertiş ◽  
Robert Săndulescu
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Electrochemical Behaviour ◽  
Great Part ◽  
Differential Pulse ◽  
Test Methods ◽  
Urine Samples ◽  
Codeine Phosphate ◽  
Carbon Electrode

AbstractElectrochemical behaviour of some alkaloids, namely: caffeine, aminophylline, theophylline, codeine phosphate and papaverine hydrochloride, that are in solution in various combinations or in the presence of other compounds contained in pharmaceuticals or in real samples (urine) was investigated using cyclic voltammetry (CV), square-wave voltammetry (SWV) and differential pulse voltammetry (DPV) on electrochemically activated glassy carbon electrode. The proposed electroanalytical methods were successfully applied in the simultaneous determination of these alkaloids in different combination or in the presence of other compounds. The great part of these combinations can be analyzed simultaneously because they practically do not interfere. The electrochemical test methods attempted to detect the presence of alkaloids in urine samples collected from subjects who consumed coffee (caffeine), and from a patient under treatment with Miofilin® (aminophylline). Urine samples were determined after filtration, without prior dilution and after dilutiion with acetate buffer at pH 4.5. Best results were obtained using DPV performed on electrochemically activated glassy carbon electrode. Thus in samples taken from subjects who drink coffee the caffeine concentration detected was 6.21×10−7 mol L−1 in the first sample and 7.77×10−7 mol L−1 in the second sample, while aminophylline concentration detected was 1.15×10−7 mol L−1.

scholarly journals Determination of β-Agonists in Urine Samples at Low µg/kg Levels by Means of Pulsed Amperometric Detection at a Glassy Carbon Electrode Coupled with RP-LC

2021 ◽  
Vol 11 (23) ◽  
pp. 11302
Author(s):  
Annalisa Mentana ◽  
Carmen Palermo ◽  
Diego Centonze
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Detection Limits ◽  
Amperometric Detection ◽  
Time Profile ◽  
Urine Samples ◽  
Carbon Electrode ◽  
Experimental Conditions ◽  
Pulsed Amperometric Detection

A method for the determination of β-agonists was developed by combining the separation of analytes through high-performance liquid chromatography, with a reversed-phase column, coupled to the pulsed amperometric detection at a glassy carbon electrode. Preliminary experiments, using cyclic voltammetry, allowed for an understanding of the electrochemical behavior of clenbuterol, fenoterol, and terbutaline. By analyzing the electrochemical response, the conditions for detecting the analytes and for cleaning the working electrode were identified. The proposed potential-time profile was designed to prevent contamination of the carbon electrode following consecutive analyses, so ensuring a reproducible and sensitive quantitative determination. The waveform electrochemical parameters, including detection and delay times, have been optimized in terms of sensitivity, detection limits, and long-term response stability. The chromatographic separation was carried out using a C8 column in isocratic mode, and a mixture of acetic acid and acetonitrile. The optimized experimental conditions were used for the analysis of standard solutions and real samples. Detection limits, lower than the maximum residue limit set for clenbuterol by European directives, were obtained for all β-agonists investigated. The method validation was performed by evaluating the linearity, selectivity, precision, and recovery. Calf urine samples were used to verify the applicability of the proposed method, analyzing both enriched and naturally contaminated urine samples.

scholarly journals Computerized cyclic voltammetric detection after HPLC of the antineoplastic agents etoposide, teniposide, adriamycin and its metabolite adriamycinol in urine samples

1989 ◽  
Vol 11 (3) ◽  
pp. 106-112 ◽  
Author(s):  
H. H. J. L. Ploegmakers ◽  
P. A. Moritz ◽  
P. J. M. M. Toll ◽  
W. J. van Oort
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Antineoplastic Agents ◽  
Urine Samples ◽  
Carbon Electrode ◽  
Cyclic Voltammetric ◽  
Mercury Drop Electrode ◽  
Voltammetric Detection

Based on their concentrations in urine, the oxidative cyclic voltammetric mode, using a glassy carbon electrode, permits the determination of etoposide and teniposide, whereas the reductive cyclic voltammetric mode, with a static mercury drop electrode, permits the determination of adriamycin and its metabolite adriamycinol.

Voltammetric Determination of Guaifenesin in Pharmaceuticals and Urine Samples Based on Poly(Bromocresol Purple) Modified Glassy Carbon Electrode

2020 ◽  
Vol 16 (5) ◽  
pp. 633-639
Author(s):  
Fatma Ağın
Keyword(s):  
Differential Pulse Voltammetry ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Urine Samples ◽  
Bromocresol Purple ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Pulse Voltammetry

Introduction: The electro-oxidation behavior of expectorant drug Guaifenesin (GUF) was studied on poly(bromocresol purple) modified Glassy Carbon Electrode (GCE) by Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) methods. Materials and Methods: GCE was modified with electropolymerization of Bromocresol Purple (BP) monomer for sensitive determination of GUF with voltammetric methods. The oxidation process of GUF showed irreversible and diffusion controlled behavior. The linearity has been obtained in the range from 1.00 × 10-7 to 2.00 × 10-5 M with the limit of detection 3.658 × 10-9 M for DPV in 0.1 M phosphate buffer solution (PBS) at pH 3.0. Results and Conclusion: Fully validated differential pulse voltammetry was successfully applied for the determination of GUF in pharmaceutical dosage forms and urine samples obtained satisfying results.

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