Catalytic hydrogen evolution in cathodic stripping voltammetry on a mercury electrode in the presence of cobalt(ii) ion and phenylthiourea or thiourea

The Analyst ◽  
2001 ◽  
Vol 126 (11) ◽  
pp. 1907-1911 ◽  
Author(s):  
Nicolae Spătaru ◽  
Florinel Gabriel Bănică
Keyword(s):  
Hydrogen Evolution ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Cathodic Stripping Voltammetry ◽  
Catalytic Hydrogen ◽  
Catalytic Hydrogen Evolution ◽  
Cathodic Stripping

Electrochemical determination of muscle relaxant drug tetrazepam in bulk form, pharmaceutical formulation, and human serum

2008 ◽  
Vol 62 (2) ◽  
Author(s):  
Mohammed Ghoneim ◽  
Hanaa El-Desoky ◽  
Mohammed El-Ries ◽  
Ashraf Abd-Elaziz
Keyword(s):  
Human Serum ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Differential Pulse Polarography ◽  
Linear Sweep ◽  
Square Wave ◽  
Cathodic Stripping Voltammetry ◽  
Cathodic Stripping

AbstractTetrazepam dissolved in the Britton-Robinson universal buffer of various pH values (2.5–11.5) containing 10 vol. % of ethanol was reduced at the mercury electrode in a single 2-electron irreversible step due to reduction of the 4,5 C=N double bond of the seven-membered ring. Differential pulse polarography (DPP) and adsorptive cathodic stripping voltammetry (AdCSV) techniques (Linear sweep LS, differential pulse DP and square-wave SW modes) for quantification of tetrazepam in bulk form and in myolastan tablets are presented. Moreover, the described linear sweep, differential pulse, and square-wave adsorptive cathodic stripping voltammetry was successfully applied in quantification of tetrazepam in spiked human serum without any prior extraction of the drug. The obtained results showed an increased sensitivity of the described electro-analytical procedures for the quantification of tetrazepam in the following order DPP, DP-AdCSV, LS-AdCSV, and SW-AdCSV, since the observed limits of tetrazepam quantitation by these electroanalytical techniques were 5 × 10−6 mol L−1, 3 × 10−7 mol L−1, 1 × 10−8 mol L−1, and 3 × 10−9 mol L−1, respectively.

Cathodic Stripping Voltammetry of 2-Thiouracils

2005 ◽  
Vol 70 (2) ◽  
pp. 188-197 ◽  
Author(s):  
Michał Kasprzak ◽  
Witold Ciesielski ◽  
Sławomira Skrzypek
Keyword(s):  
Analytical Method ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Antithyroid Drugs ◽  
Chemical Reagents ◽  
Cathodic Stripping Voltammetry ◽  
Electrode Reactions ◽  
Adsorption Processes ◽  
Cathodic Stripping

Four 6-R-2-thiouracils (R = H, methyl, propyl, benzyl) were examined by differential pulse cathodic stripping voltammetry on mercury electrode. The research led to a very sensitive analytical method that allows their determination on nanomolar level. The detection limit of the 6-propyl derivative is as low as 1.0 × 10-9 mol dm-3. The procedure is very simple and utilizes only most common chemical reagents (such as acetate buffer). The buffer concentration plays an important role in the preconcentration stage, due to the adsorption processes accompanying electrode reactions. The new analytical method was tested with commercial samples of various antithyroid drugs.

scholarly journals Voltammetric characteristics of miconazole and its cathodic stripping voltammetric determination

2002 ◽  
Vol 74 (3) ◽  
pp. 425-432 ◽  
Author(s):  
FRANCISCO C. PEREIRA ◽  
NELSON R. STRADIOTTO ◽  
MARIA VALNICE B. ZANONI
Keyword(s):  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Large Contribution ◽  
Compound Formation ◽  
Cathodic Stripping Voltammetry ◽  
Voltammetric Characteristics ◽  
Relative Standard ◽  
Limit Detection ◽  
Cathodic Stripping

Miconazole is reduced at mercury electrode above pH 6 involving organometallic compound formation, responsible for an anomalous polarographic behavior. The electrodic process presents a large contribution of the adsorption effects. The drug can be determined by cathodic stripping voltammetry from 8.0 x 10-8 to 1, 5 x 10-6 molL-1 in Britton-Robinson buffer pH 8.0, when pre-accumulated for 30s at an accumulation potential of 0V. A relative standard deviation of 3.8% was obtained for ten measurements of 1.0 x 10-7 molL-1 miconazole in B-R buffer pH 8.0 and a limit detection of 1, 7 x 10-8 molL-1 was determined using 60s of deposition time and scan rate of 100 mVs-1. The proposed method is simple, precise and it was applied successfully for the determination of the miconazole in pure form and in commercial formulations, showing mean recoveries of 99.7-98.4%.

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