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.

Three validated stripping voltammetric procedures for determination of the anti-prostate cancer drug flutamide in tablets and human serum at a mercury electrode

2004 ◽  
Vol 82 (9) ◽  
pp. 1386-1392 ◽  
Author(s):  
E Hammam ◽  
H S El-Desoky ◽  
K Y El-Baradie ◽  
A M Beltagi
Keyword(s):  
Prostate Cancer ◽  
Human Serum ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Pharmaceutical Formulation ◽  
Cancer Drug ◽  
Linear Sweep ◽  
Square Wave

Flutamide is a nonsteriodal anti-androgen drug, which is commonly used in the treatment of advanced prostate cancer. Based on the reduction of the nitro organic moiety of the drug molecule in acetate buffer of pH 5 at the hanging mercury drop electrode, three adsorptive cathodic stripping voltammetric procedures were optimized for determination of flutamide in bulk, tablets, and human serum applying linear-sweep, differential-pulse, and square-wave waveforms. The achieved limits of detection of the bulk drug were 1.9 × 10–7, 8.7 × 10–8, and 9.7 × 10–9 mol L–1 by using the optimized differential-pulse, linear-sweep, and square-wave adsorptive stripping voltammetric procedures, respectively. Repeatability of the results was studied for 1 × 10–6 mol L–1 of the drug and the recoveries obtained were 98.51 ± 1.56% (LSV), 98.89 ± 0.87% (DPV), and 99.21 ± 1.03% (SWV). The proposed procedures were successfully applied to the determination of the drug in pharmaceutical formulation (Eulexin® tablets) and human serum. The detection limits of the drug in bulk, pharmaceutical formulation, and human serum achieved by means of the proposed procedures showed that the square-wave mode was more reliable for determination of the drug especially in its low concentration levels.Key words: flutamide, linear-sweep, differential-pulse, square-wave, cathodic adsorptive stripping voltammetry, determination, Eulexin® tablets, human serum.

Determination of Arsenic and Selenium in Foods By Electroanalytical Techniques

1976 ◽  
Vol 59 (3) ◽  
pp. 650-654 ◽  
Author(s):  
Walter Holak
Keyword(s):  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Magnesium Nitrate ◽  
Differential Pulse Polarography ◽  
Cathodic Stripping Voltammetry ◽  
Pulse Polarography ◽  
Trivalent State ◽  
Relative Standard ◽  
Cathodic Stripping

Abstract Arsenic and selenium are determined in foods by differential pulse polarography and cathodic stripping voltammetry. The sample is digested with nitric acid and magnesium nitrate and then dissolved in dilute hydrochloric acid. An aliquot is removed, the arsenic is chemically reduced to the trivalent state, and interferences are removed by ion exchange before polarography. Selenium is determined in a second aliquot by cathodic stripping voltammetry. Recoveries for both elements in several foods were from 90 to 110%. The relative standard deviations for arsenic at 5 ppm and selenium at 0.48 ppm were 5.8 and 7.3%, 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 quantitation at the mercury electrode of the anticholinergic drug flavoxate hydrochloride in bulk and in a pharmaceutical formulation

2007 ◽  
Vol 5 (2) ◽  
pp. 496-507 ◽  
Author(s):  
M.M. Ghoneim ◽  
M.A. El-Attar ◽  
S.A. Razeq
Keyword(s):  
Anticholinergic Drug ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Pharmaceutical Formulation ◽  
Differential Pulse Polarography ◽  
Linear Sweep ◽  
Square Wave ◽  
Pulse Polarography ◽  
Dc Polarography ◽  
Flavoxate Hydrochloride

AbstractFlavoxate hydrochloride, 2-piperidinoethyl 3-methyl-4-oxo-2-phenyl-4-H-chromene-8-carboxylate, is a smooth muscle antispasmodic. Its electrochemical behavior was studied at the mercury electrode in buffered solutions containing 30% (v/v) methanol using dc-polarography, differential-pulse polarography, cyclic voltammetry, and linear sweep-and square-wave adsorptive stripping voltammetry. Sensitive and precise procedures were developed for determination of bulk flavoxate hydrochloride and in the pharmaceutical formulation Genurin® S.F, without sample pretreatment or extraction. Limits of quantitation (LOQ) of 1 × 10−5, 5 × 10−6, 1 × 10−8 and 1 × 10−9 M flavoxate hydrochloride were achieved by dc-polarography, differential-pulse polarography, linear sweep and square-wave adsorptive stripping voltammetric, respectively.

Reaction of nucleic acid bases with the mercury electrode: determination of submicromolar concentrations of pyrimidine bases by means of cathodic stripping voltammetry

1980 ◽  
Vol 45 (12) ◽  
pp. 3472-3481 ◽  
Author(s):  
Emil Paleček ◽  
František Jelen
Keyword(s):  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Deposition Potential ◽  
Pyrimidine Derivatives ◽  
Cathodic Stripping Voltammetry ◽  
Order Of Magnitude ◽  
Pyrimidine Bases ◽  
Cathodic Stripping

Pyrimidine bases commonly occurring in nucleic acids i.e. cytosine, uracil and thymine and further pyrimidine derivatives such as 5-methylcytosine, 5-hydroxymethylcytosine, isocytosine, uracil-6-carboxylic acid (orotic acid), 5-amino-2,4-dioxypyrimidine, 2-amino-4,6-dioxypyrimidine and 4-amino-2,6-dioxypyrimidine and thio derivatives and halogen derivatives of uracil and cytosine were analyzed by means of cathodic stripping voltammetry (CSV). As compared with most of the sulphur-containing substances the deposition potential optima of the pyrimidine derivatives (not containing sulphur) were substantially narrower and shifted to more positive potentials. Cytosine, thymine and uracil can be determined by means of differential pulse CSV at concentrations of the order of magnitude 10-7 - 10-8 mol/l. Nucleosides and nucleotides derived from the pyrimidine bases are inactive and do not substantially interfere with the determination of bases. Bases can be determined even in an excess of DNA and proteins.

Polarographic and Voltammetric Determination of Trace Amounts of 3-Nitrofluoranthene

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1571-1587 ◽  
Author(s):  
Karel Čížek ◽  
Jiří Barek ◽  
Jiří Zima
Keyword(s):  
River Water ◽  
Solid Phase ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Separation And Preconcentration

The polarographic behavior of 3-nitrofluoranthene was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a dropping mercury electrode, differential pulse voltammetry (DPV) and adsorptive stripping voltammetry (AdSV), both at a hanging mercury drop electrode. Optimum conditions have been found for its determination by the given methods in the concentration ranges of 1 × 10-6-1 × 10-4 mol l-1 (DCTP), 1 × 10-7-1 × 10-4 mol l-1 (DPP), 1 × 10-8-1 × 10-6 mol l-1 (DPV) and 1 × 10-9-1 × 10-7 mol l-1 (AdSV), respectively. Practical applicability of these techniques was demonstrated on the determination of 3-nitrofluoranthene in drinking and river water after its preliminary separation and preconcentration using liquid-liquid and solid phase extraction with the limits of determination 4 × 10-10 mol l-1 (drinking water) and 2 × 10-9 mol l-1 (river water).

Voltammetric study of 2-guanidinobenzimidazole: Electrode mechanism and determination at mercury electrode

2011 ◽  
Vol 76 (12) ◽  
pp. 1699-1715 ◽  
Author(s):  
Sławomira Skrzypek ◽  
Valentin Mirceski ◽  
Sylwia Smarzewska ◽  
Dariusz Guziejewski ◽  
Witold Ciesielski
Keyword(s):  
Time Window ◽  
Mercury Electrode ◽  
Linear Sweep Voltammetry ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Protonated Form ◽  
Citrate Buffer ◽  
Square Wave ◽  
Biological Interest ◽  
Square Wave Stripping Voltammetry

Although 2-guanidinobenzimidazole (GBI; CAS: 5418-95-1) is a compound of biological interest, generally there is a lack of electrochemical studies and the methods of its determination. The GBI behavior at a mercury electrode was analyzed under conditions of linear sweep voltammetry (LSV), differential pulse voltammetry (DPV), square-wave voltammetry (SWV) and square-wave stripping voltammetry (SWSV). Although GBI is electrochemically inactive at mercury electrode it adsorbs at the mercury surface and catalyzes effectively the hydrogen evolution reaction. Theoretical analysis of two possible pathways, according to which the GBI electrode mechanism can be explained, is performed. Simple analysis of peak current and potential with respect to available time window, i.e. change of frequency can be helpful in discerning the character of the recorded SW current. The established electrode mechanism is assumed to involve a preceding chemical reaction in which the adsorbed catalyst (GBIads) is protonated and the protonated form of the catalyst (GBIH+(ads)) is irreversibly reduced at potential about –1.18 V vs Ag|AgCl (citrate buffer pH 2.5). New methods of voltammetric determination of 2-guanidinobenzimidazole were developed. The detection and quantifications limits were found to be 1 × 10–7, 1 × 10–6 mol l–1 (SWV); 8 × 10–8, 9 × 10–7 mol l–1 (SWSV); 4 × 10–7, 2 × 10–6 mol l–1 (DPV) and 6 × 10–7, 3 × 10–6 mol l–1 (LSV), respectively.

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