Application of reverse pulse polarography to the determination of substances which form films electrochemically on the mercury electrode

Fonseca, Juan Miguel López; Otero, A.; Monteagudo, J. C. García

doi:10.1016/0039-9140(88)80017-1

Cited by 11 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several methods are reported for spectrophotometric determination using chromogenic reagents (21)(22), its reducing action (23)(24)(25), employing charge transfer complexation (26) or difference spectrophotometry (27). Fluorimetric methods (28)(29), polarographic and voltammetric (30,31) and chromatographic methods (32)(33)(34) were also reported.…”

Section: Introductionmentioning

confidence: 99%

Spectrophotometric Determination of Captopril and Penicillamine through the Use of Ligand Exchange Complexation Reactions

Belal,

El-Walily,

Abdel-Razak

et al. 2011

Int. J Biomed Sci.

View full text Add to dashboard Cite

Two spectrophotmetric methods based on combined redox - ligand exchange reactions were developed for the determination of captopril and penicillamine in pure form and in their dosage forms. The first method is based on attenuating the absorbance of a ternary complex: silver (I) - bromopyrogallol red - phenanthroline in a buffer solution of pH6-8. The method has the concentration ranges 2-10 µg mL-1 and 0.5-1.75 µg mL-1 for captopril and penicillamine respectively, and the detection limits 7.1 × 10-2 and 5.7 × 10-2 µg mL-1 for captopril and penicillamine respectively. The second method is based on decreasing the absorbance of a chloroformic solution of copper (II) - oxine chelate when shaken with the drug solution in buffer medium of pH 8. The drugs were determined in the concentrations 30-90 µg mL-1 and 30-100 µg mL-1 for captopril and penicillamine respectively, and the detection limits 0.94 and 1.76 µg mL-1 for captopril and penicillamine respectively. The proposed methods were applied in the analysis of both compounds in their pharmaceutical preparations, and results were favorably compared with reference spectrophotometric methods regarding accuracy and precision.

show abstract

Section: Introductionmentioning

confidence: 99%

Spectrophotometric Determination of Captopril and Penicillamine through the Use of Ligand Exchange Complexation Reactions

Belal,

El-Walily,

Abdel-Razak

et al. 2011

Int. J Biomed Sci.

View full text Add to dashboard Cite

show abstract

“…In addition, the film is subsequently stripped off from the electrode surface by appropriate cathodic potential scan. This method was widely used for determination of miscellaneous inorganic ions [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and organic compounds [3,12,13,[20][21][22][23][24][25] with the detection limits within the range of 5 × 10 ¹7 to 5 × 10 ¹9 mol dm ¹3 .…”

Section: Introductionmentioning

confidence: 99%

“…Besides, the applied technique during the cathodic stripping scan plays an important role. It was shown that pulse techniques provide higher sensitivity in comparison with linear potential scan voltammetry [7,14,18,19,25]. Among them, the most advanced technique is square-wave voltammetry.…”

Section: Introductionmentioning

confidence: 99%

“…Numerous inorganic ions, such as halides [3,[7][8][9][10][11], cyanide [12], thiosulfate and sulfite [32] react according to Reaction I. Moreover, some of the sulfur containing organic compounds, such as various thiols [3,12,13,[20][21][22][23][24][25] and thioamides [33] react according to Reaction II. In this article, a theoretical model of a second order redox reaction, under conditions of square-wave voltammetry, is developed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Cathodic Stripping Square-Wave Voltammetry of a Second-Order Redox Reaction and Its Application to the Mercury-Cysteine System

Mirčeski

Lovrić

1998

Electroanalysis

View full text Add to dashboard Cite

A model of cathodic stripping square-wave voltammetry of a second-order redox reaction is developed. Both reversible and quasireversible redox reactions are considered. The relationships between the properties of SWV response and both parameters of the redox reaction and the SWV excitation signal are analyzed. The effect of the concentration of the reacting ligand on the SW voltammograms is discussed. The phenomenon of a quasireversible maximum is demonstrated. Numerical simulations are compared qualitatively with the cathodic stripping square-wave voltammetric response of cysteine.

show abstract

Quasireversible Maximum in Cathodic Stripping Square-Wave Voltammetry

Mirčeski

Lovrić

1999

Electroanalysis

View full text Add to dashboard Cite

Square‐wave voltammetry of the cathodic stripping processes exhibits maximum response for a quasireversible redox reaction. This phenomenon, known as a “quasireversible maximum” is explored for kinetic measurements of this class of redox reactions. The apparent reversibility of a redox reaction, together with the position of the quasireversible maximum, depend on the single complex kinetic parameter K, which is defined through the standard rate constant, diffusion coefficient of the ligand and frequency of the SW signal. Critical values of the kinetic parameter Kmax are theoretically calculated for different values of the transfer coefficient α and amplitudes of the signal. If the frequency which corresponds to the quasireversible maximum is experimentally obtained, the standard rate constant of the investigated redox reaction could be estimated. Standard rate constant can be defined either in units cm s–1, which is the same as for a redox reaction of a dissolved redox couple, or only in s–1, which is typical for a redox reaction of an adsorbed redox couple. This feature shows that cathodic stripping redox reactions are an important class of redox reactions which can be regarded as an intermediate form between the redox processes of adsorbed and dissolved redox couple.

show abstract

Application of reverse pulse polarography to the determination of substances which form films electrochemically on the mercury electrode

Cited by 11 publications

References 12 publications

Spectrophotometric Determination of Captopril and Penicillamine through the Use of Ligand Exchange Complexation Reactions

Spectrophotometric Determination of Captopril and Penicillamine through the Use of Ligand Exchange Complexation Reactions

A Cathodic Stripping Square-Wave Voltammetry of a Second-Order Redox Reaction and Its Application to the Mercury-Cysteine System

Quasireversible Maximum in Cathodic Stripping Square-Wave Voltammetry

Contact Info

Product

Resources

About