Differential Pulse Polarographic Analysis of Thyroid Hormone: Determination of Iodine, Thyroxine, and Liothyronine

1979 ◽  
Vol 68 (3) ◽  
pp. 338-342 ◽  
Author(s):  
Walter Holak ◽  
Donald Shostak
Keyword(s):  
Thyroid Hormone ◽  
Differential Pulse ◽  
Polarographic Analysis

Polarographic Analytical Study of Oxyphenbutazone

1981 ◽  
Vol 64 (6) ◽  
pp. 1439-1441
Author(s):  
Moustafa M Ellaithy ◽  
M Fayez El-Tarras ◽  
Sawsan M Amer
Keyword(s):  
Analytical Study ◽  
Pharmaceutical Formulations ◽  
Differential Pulse ◽  
Polarographic Behavior ◽  
Polarographic Analysis ◽  
Inflammatory Agent ◽  
Diffusion Controlled ◽  
Anti Inflammatory

Abstract The polarographic behavior of the widely used anti-inflammatory agent, oxyphenbutazone, was studied. It is determined polarographically by conversion to the nitroso derivative characterized by a cathodic, irreversible, diffusion-controlled wave. The method is applied to the determination of 2.5-10 mg/100 mL of oxyphenbutazone, with an accuracy of 99.9 ± 1.38%. By differential pulse polarographic analysis, as little as 10 ppm oxyphenbutazone can be determined with an accuracy of 99.70 ± 0.99% in pure powder and in some pharmaceutical formulations.

Polarographic and Colorimetric Methods for Determination of Cyclophosphamide

1984 ◽  
Vol 67 (4) ◽  
pp. 679-681
Author(s):  
Moustafa M Ellaithy ◽  
M Fayez El-Tarras ◽  
Nabil B Tadros ◽  
Mohamed M Amer
Keyword(s):  
Linear Relationship ◽  
Nitrous Acid ◽  
Differential Pulse ◽  
Dosage Forms ◽  
Lemon Yellow ◽  
Colorimetric Analysis ◽  
Polarographic Analysis ◽  
Diffusion Controlled ◽  
Colorimetric Methods

Abstract Polarographic and colorimetric methods for analysis of cyclophosphamide and its dosage forms were investigated. Both methods are based on the reaction of cyclophosphamide with nitrous acid. A single cathodic diffusion-controlled wave was used for dc polarographic determination of cyclophosphamide, with an accuracy of 99.98 ± 1.09%. The wave was well defined and irreversible. By differential pulse polarographic analysis, as little as 10 ppm cyclophosphamide was determined; overall accuracy at 10-60 ppm was 100.16 ± 0.99%. The linear relationship between absorbance for the lemon-yellow nitroso derivative and the concentration of cyclophosphamide was further used in colorimetric analysis; overall accuracy was 100.2 ± 0.99%.

Analysis of Nicotine in Antismoking Pharmaceutical Products by Differential Pulse Polarography and Voltammetry

2007 ◽  
Vol 72 (9) ◽  
pp. 1207-1213 ◽  
Author(s):  
Atle Hannisdal ◽  
Øyvind Mikkelsen ◽  
Knut H. Schrøder
Keyword(s):  
Supporting Electrolyte ◽  
Extraction Procedure ◽  
Pharmaceutical Formulations ◽  
Differential Pulse ◽  
Pharmaceutical Products ◽  
Chewing Gum ◽  
Simple Liquid ◽  
Polarographic Analysis ◽  
Dropping Mercury Electrode

A fast and simple differential pulse polarographic method was developed for analysis of nicotine in various pharmaceutical formulations (chewing gum, tablets (drops) and patches). This method requires a simple liquid-liquid extraction procedure for chewing gum and patches, or a direct dilution in supporting electrolyte for tablets before polarographic analysis. The polarographic analysis was done in a Britton-Robinson buffer (pH 6.2) as supporting electrolyte. The multimode electrode from Metrohm was used as working electrode (dropping mercury electrode). This method was applied to the determination of the nicotine content in chewing gum, tablets and patches by using the standard addition method. The results are in good agreement with the content declared by the manufacturer. The method is fast, simple and reliable, and it is a complementary method to the chromatographic method being used today for quantitative analysis of nicotine in pharmaceutical formulations. The limit of quantification is assumed to be far below 0.1 mg/l in the polarographic vessel. The method uses simple dilution and/or extraction procedures for sample preparation before polarographic analysis. It is also shown that it is possible to use a glassy carbon electrode with a mercury film (MTFE electrode) for the determination of nicotine in antismoking pharmaceutical products.

scholarly journals DEVELOPMENT AND VALIDATION OF DIFFERENTIAL PULSE POLAROGRAPHIC ANALYSIS OF FENOFIBRATE IN PURE AND PHARMACEUTICAL DOSAGE FORMS USING DROPPING MERCURY ELECTRODE

2016 ◽  
Vol 8 (10) ◽  
pp. 284
Author(s):  
Abdul Aziz Ramadan ◽  
Hasna Mandil ◽  
Reham Abu-saleh
Keyword(s):  
Limit Of Detection ◽  
Mercury Electrode ◽  
Reference Method ◽  
Differential Pulse ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Polarographic Analysis ◽  
Relative Standard ◽  
Dropping Mercury Electrode

<p><strong>Objective: </strong>An easy, fast, accurate and sensitive differential pulse polarographic analysis for determination of fenofibrate (FEN) in pure and pharmaceutical dosage forms using dropping mercury electrode (DME) was applied.</p><p><strong>Methods: </strong>The method involves the electrochemical reduction of fenofibrate at DME by differential pulse polarographic analysis (DPPA). Different buffer solutions were used over a wide pH range (1.0–10.0). The best definition of the analytical signals was found in lithium perchlorate trihydrate buffer at pH 6.0 containing 24% (v/v) acetonitrile at-994 to-1025mV (versus Ag/AgCl).</p><p><strong>Results: </strong>Under optimized conditions the peak current (I<sub>p</sub>) is linear over the range 0.0361-3.608 μg/ml. The DPPA was used successfully for the determination of FEN in pure and pharmaceutical dosage forms. The relative standard deviation did not exceed 2.1% for the concentration of FEN 0.0361 μg/ml. Regression analysis showed a good correlation coefficient (R<sup>2</sup>= 0.9994) between Ip and concentration at the mentioned range. The limit of detection (LOD) and the limit of quantification (LOQ) was to be 0.0025 and 0.0076 μg/ml, respectively. The proposed method was validated for linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ), robustness and specificity with an average recovery of 99.8-100.6%.</p><p><strong>Conclusion: </strong>The developed method is applicable for the determination of FEN in pure and different dosage forms with the assay of marketed formulations 99.8-104.0% and the results are in good agreement with those obtained by square-wave voltammetry (SWV) reference method.</p><p><strong>Keywords: </strong>Differential pulse polarographic analysis, Fenofibrate, Pharmaceutical formulations</p>

Differential Pulse Voltammetric Determination of Piroxicam on Lanthanide Ferric Oxide Nanoparticles-Carbon Paste Modified Electrode

2018 ◽  
Vol 14 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Isaac Yves Lopes de Macedo ◽  
Morgana Fernandes Alecrim ◽  
Luane Ferreira Garcia ◽  
Aparecido Ribeiro de Souza ◽  
Wallans Torres Pio dos Santos ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Ferric Oxide ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Oxide Nanoparticles ◽  
Carbon Paste ◽  
Carbon Paste Modified Electrode

Graphene Modified Molecular Imprinting Electrochemical Sensor for Determining the Content of Dopamine

2019 ◽  
Vol 15 (6) ◽  
pp. 628-634
Author(s):  
Rong Liu ◽  
Jie Li ◽  
Tongsheng Zhong ◽  
Liping Long
Keyword(s):  
Electrochemical Sensor ◽  
Molecular Imprinting ◽  
Neurological Disorders ◽  
Room Temperature ◽  
Low Cost ◽  
Differential Pulse ◽  
Current Response ◽  
Specific Selectivity ◽  
Pulse Voltammetry

Background: The unnatural levels of dopamine (DA) result in serious neurological disorders such as Parkinson’s disease. Electrochemical methods which have the obvious advantages of simple operation and low-cost instrumentation were widely used for determination of DA. In order to improve the measurement performance of the electrochemical sensor, molecular imprinting technique and graphene have always been employed to increase the selectivity and sensitivity. Methods: An electrochemical sensor which has specific selectivity to (DA) was proposed based on the combination of a molecular imprinting polymer (MIP) with a graphene (GR) modified gold electrode. The performance and effect of MIP film were investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the solution of 5.0 ×10-3 mol/L K3[Fe(CN)6] and K4[Fe(CN)6] with 0.2 mol/L KCl at room temperature. Results: This fabricated sensor has well repeatability and stability, and was used to determine the dopamine of urine. Under the optimized experiment conditions, the current response of the imprinted sensor was linear to the concentration of dopamine in the range of 1.0×10-7 ~ 1.0×10-5 mol/L, the linear equation was I (µA) = 7.9824+2.7210lgc (mol/L) with the detection limit of 3.3×10-8 mol/L. Conclusion: In this work, a highly efficient sensor for determination of DA was prepared with good sensitivity by GR and great selectivity of high special recognization ability by molecular imprinting membrane. This proposed sensor was used to determine the dopamine in human urine successfully.

Determination of platinum in biological material by differential pulse polarography: Analysis in urine, plasma and tissue following sample combustion

1983 ◽  
Vol 48 (10) ◽  
pp. 2903-2908 ◽  
Author(s):  
Viktor Vrabec ◽  
Oldřich Vrána ◽  
Vladimír Kleinwächter
Keyword(s):  
Biological Material ◽  
Biological Fluid ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Linear Calibration ◽  
Catalytic Current ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

A method is described for determining total platinum content in urine, blood plasma and tissues of patients or experimental animals receiving cis-dichlorodiamineplatinum(II). The method is based on drying and combustion of the biological material in a muffle furnace. The product of the combustion is dissolved successively in aqua regia, hydrochloric acid and ethylenediamine. The resulting platinum-ethylenediamine complex yields a catalytic current at a dropping mercury electrode allowing to determine platinum by differential pulse polarography. Platinum levels of c. 50-1 000 ng per ml of the biological fluid or per 0.5 g of a tissue can readily be analyzed with a linear calibration.

Polarography of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol mixtures

1985 ◽  
Vol 50 (3) ◽  
pp. 712-725 ◽  
Author(s):  
Jiří Barek ◽  
Lubomír Kelnar
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Reduction Mechanism ◽  
Pulse Polarography ◽  
Methanol Medium

The polarographic reduction of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol medium was investigated. Evidence is presented for adsorption of the depolarizer on the electrode, and a reduction mechanism is proposed. Conditions are indicated for the determination of this compound in the concentration range 10-4-10-6 mol/l by d.c. polarography, 10-5 to 3 . 10-7 mol/l by Tast polarography, and 10-5-3 . 10-8 mol/l by differential pulse polarography.

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.

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