Polarographic and Voltammetric Determination of N,N-Dimethyl-4-amino-4'-sulfoazobenzene

1997 ◽  
Vol 62 (4) ◽  
pp. 597-608 ◽  
Author(s):  
Jiří Barek ◽  
Pham Tuan Hai ◽  
Viktor Mejstřík ◽  
Josino C. Moreira ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Test Substance ◽  
Hanging Mercury Drop Electrode ◽  
Large Area ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Constant Potential

The polarographic behaviour of N,N-dimethyl-4-amino-4'-sulfoazobenzene was investigated by tast polarography and differential pulse polarography at a dropping mercury electrode, constant-potential coulometry at a large area mercury electrode and cyclic voltammetry at a hanging mercury drop electrode. Optimum conditions have been found for its determination by tast polarography in the concentration range of 2-100 μmol l-1, differential pulse polarography at a dropping mercury electrode in the concentration range of 0.2-100 μmol l-1 and by differential pulse voltammetry at a hanging mercury drop electrode in the concentration range of 0.02-10 μmol l-1. The sensitivity of the determination can be further improved by adsorptive accumulation of the test substance on the hanging mercury drop electrode. Three-minute accumulation in stirred solution allows determination in the range of 0.2-100 nmol l-1.

Polarographic and Voltammetric Determination of 1-(4-Methoxyphenyl)-3-methyltriazene

1996 ◽  
Vol 61 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Jiří Barek ◽  
Eva Pertileová ◽  
Viktor Mejstřík ◽  
Josino C. Moreira ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Test Substance ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Large Area ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

The polarographic behaviour of 1-(4-methoxyphenyl)-3-methyltriazene in a mixed aqueous-methanolic medium was investigated by tast polarography and differential pulse polarography at a dropping mercury electrode, constant-potential coulometry at a large area mercury electrode and cyclic voltammetry at a hanging mercury drop electrode. A mechanism has been proposed for its polarographic reduction and optimal conditions have been found for its determination by tast polarography in the concentration range 2-100 μmol l-1 and by differential pulse polarography at a dropping mercury electrode, differential pulse voltammetry at a hanging mercury drop electrode and linear scan voltammetry at a hanging mercury drop electrode in the concentration range 0.2-100 μmol l-1. The sensitivity of the determination can be further improved through adsorptive accumulation of the test substance on the surface of the hanging mercury drop electrode; fifteen-second accumulation in stirred solution allows determination in the range 0.01-0.1 μmol l-1.

The Polarographic and Voltammetric Determination of N,N-Dimethyl-4-amino-3'-nitroazobenzene

1993 ◽  
Vol 58 (2) ◽  
pp. 295-309 ◽  
Author(s):  
Jiří Barek ◽  
Dana Dřevínková ◽  
Viktor Mejstřík ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Test Substance ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

The polarographic reduction of N,N-dimethyl-4-amino-3'-nitroazobenzene was studied by tast polarography and differential pulse polarography, constant potential coulometry and cyclic voltammetry and mechanism was proposed for the reduction. Optimal conditions were found for the determination of the test substance using tast polarography in concentration range 1 . 10-4 - 2 . 10-6 mol l-1, differential pulse polarography at classical dropping mercury electrode and fast scan differential pulse voltammetry at a hanging mercury drop electrode in range 1 . 10-4 - 2 . 10-7 mol l-1 and linear scan voltammetry at a hanging mercury drop electrode in range 1 . 10-5 - 2 . 10-8 mol l-1. A further increase in the sensitivity was achieved through adsorptive accumulation of the test substance on the surface of the working electrode, permitting the determination to be carried out in the concentration range 1 . 10-7 - 2 . 10-9 mol l-1.

The polarographic and voltammetric determination of trypane blue

1988 ◽  
Vol 53 (5) ◽  
pp. 921-928
Author(s):  
Jiří Barek ◽  
Janina Balsiene ◽  
Barbara Tietzová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Pulse Voltammetry

The reduction of mutagenic bisazodye trypane blue has been studied at a mercury electrode, a mechanism has been proposed and optimal conditions found for its analytical application. The use of a dropping mercury electrode with a renewable surface yielded a detection limit of 8 . 10-7 mol l-1 for TAST polarography, and 8 . 10-8 mol l-1 for differential pulse polarography; the use of a hanging mercury drop electrode with an unrenewed surface during the measurement yielded detection limit of 6 . 10-8 mol l-1 for fast scan differential pulse voltammetry and 4 . 10-8 mol l-1 for linear scan voltammetry. Preliminary adsorptive accumulation of the determined substance on the surface of the hanging mercury drop electrode led to a decrease in the detection limit to 5 . 10-9 mol l-1 for linear scan voltammetry.

The Polarographic and Voltammetric Determination of 1(4'-Carbamoylphenyl)-3,3-dimethyltriazene

1992 ◽  
Vol 57 (6) ◽  
pp. 1230-1236
Author(s):  
Jiří Barek ◽  
Viktor Mejstřík ◽  
Saafa Toubar ◽  
Jiří Zima
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Test Substance ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Polarographic Behaviour ◽  
Pulse Polarography ◽  
Pulse Voltammetry

A study was made of the polarographic behaviour of 1-(4'-carbamoylphenyl)-3,3-dimethyltriazene and optimum conditions were found for its determination by tast polarography and differential pulse polarography at a static mercury drop electrode and by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-4 to 2 . 10-7 mol l-1. A further increase in the sensitivity can be achieved through adsorptive accumulation of the test substance on the surface of a hanging mercury drop, permitting the determination to be extended to the concentration range 1 . 10-7 - 2 . 10-9 mol l-1.

Polarographic and Voltammetric Determination of Submicromolar Concentrations of Genotoxic 1,5-Dinitronaphthalene

2004 ◽  
Vol 69 (11) ◽  
pp. 2021-2035 ◽  
Author(s):  
Kumaran Shanmugam ◽  
Jiří Barek ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Pulse Voltammetry

Polarographic and voltammetric behavior of 1,5-dinitronaphthalene was investigated using tast polarography and differential pulse polarography at a classic dropping mercury electrode and differential pulse voltammetry and adsorptive stripping voltammetry at a hanging mercury drop electrode. Optimum conditions have been found for the determination of tested substance in the concentration range 2-10 μmol l-1 in tast polarography, 0.2-1 μmol l-1 in differential pulse polarography at a classic dropping mercury electrode or differential pulse voltammetry at a hanging mercury drop electrode, and 0.02-0.1 μmol l-1 using adsorptive stripping voltammetry. A possible mechanism of the electrochemical reduction of 1,5-dinitronaphthalene at mercury electrodes is discussed.

Polarographic and voltammetric determination of 6-nitrobenzimidazole and mechanism of its electrochemical reduction

2009 ◽  
Vol 74 (10) ◽  
pp. 1443-1454 ◽  
Author(s):  
Dana Deýlová ◽  
Jiří Barek ◽  
Vlastimil Vyskočil
Keyword(s):  
Electrochemical Reduction ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Constant Potential ◽  
Pulse Voltammetry

Optimal conditions were found for the determination of 6-nitrobenzimidazole by tast polarography (at 1 × 10–4–1 × 10–6 mol l–1), by differential pulse polarography at dropping mercury electrode (at 1 × 10–4–1 × 10–7 mol l–1), and by differential pulse voltammetry at hanging mercury drop electrode (at 1 × 10–4–1 × 10–8 mol l–1). Practical applicability of the developed methods was verified on the determination of 6-nitrobenzimidazole in drinking water (at 10–8 mol l–1). Coulometry at constant potential and cyclic voltammetry were used for elucidation of the mechanism of electrochemical reduction.

The polarographic and voltammetric determination of semitrypane blue

1989 ◽  
Vol 54 (6) ◽  
pp. 1538-1548
Author(s):  
Jiří Barek ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Dropping Mercury Electrode ◽  
Pulse Voltammetry

The polarographic reduction of the azodye semitrypane blue has been studied, a mechanism has been proposed and optimal conditions have been found for the determination of this substance by TAST polarography (to 2.10-6 mol l-1) and differential pulse polarography (to 1.10-7 mol l-1) at a classical dropping mercury electrode and by fast scan differential pulse voltammetry (to 1.10-8 mol l-1) and linear scan voltammetry (to 1.10-8 mol l-1) at a hanging mercury drop electrode. The detection limit was decreased to 1.10-9 mol l-1 for fast scan differential pulse voltammetry and 1.10-10 mol l-1 for linear scan voltammetry by using adsorptive accumulation of the determined substance at the hanging mercury drop electrode.

Polarographic and voltammetric study of genotoxic 2,7-dinitrofluoren-9-one and its determination using mercury electrodes

2009 ◽  
Vol 74 (11-12) ◽  
pp. 1675-1696 ◽  
Author(s):  
Vlastimil Vyskočil ◽  
Jiří Barek
Keyword(s):  
Solid Phase ◽  
Mercury Electrode ◽  
Direct Determination ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Dropping Mercury Electrode ◽  
Separation And Preconcentration

Electrochemical behavior of genotoxic 2,7-dinitrofluoren-9-one was investigated by DC polarography and DC tast polarography, both at a dropping mercury electrode, and by cyclic voltammetry at a hanging mercury drop electrode, in buffered aqueous-methanolic solutions. The number of exchanged electrons was determined by constant-potential coulometry at a mercury pool electrode. A possible mechanism of the electrochemical reduction has been proposed. Optimal conditions were found for the determination of 2,7-dinitrofluoren-9-one by DC tast polarography in the concentration range from 2 × 10–6to 1 × 10–5mol l–1and by differential pulse polarography (from 2 × 10–7to 1 × 10–5mol l–1), both at dropping mercury electrode, by differential pulse voltammetry (from 2 × 10–8to 1 × 10–5mol l–1) and by adsorptive stripping voltammetry (from 2 × 10–9to 1 × 10–7mol l–1), both at hanging mercury drop electrode. Practical applicability of the developed methods was verified on the direct determination of 2,7-dinitrofluoren-9-one in drinking water in 10–8mol l–1concentration range, and in drinking and river water (both in 10–9mol l–1concentration range) using preliminary separation and preconcentration by solid-phase extraction.

Polarographic and voltammetric determination of 1-(2’-carbamoylphenyl)-3,3-dimethyltriazene

1991 ◽  
Vol 56 (10) ◽  
pp. 2073-2081 ◽  
Author(s):  
Jiří Barek ◽  
Safa Toubar ◽  
Jiří Zima
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Test Substance ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Polarographic Behaviour ◽  
Pulse Polarography ◽  
Pulse Voltammetry

A study was carried out of the polarographic behaviour of the genotoxic substance 1-(2’-carbamoylphenyl)-3,3-dimethyltriazene and optimum conditions were found for its determination by tast polarography or differential pulse polarography at a static mercury drop electrode and by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-4 -2 . 10-7 mol 1-1. The sensivity of the determination can be further improved through adsorptive accumulation of the test substance on the surface of the hanging mercury drop electrode; five-minute accumulation in unstirred solution permits determination in the concentration range (2-10 . 10-8 mol 1-1 and two-minute accumulation in stirred solution allows determination in the range (2-10) . 10-9 mol 1-1.

The polarographic and voltammetric determination of 2,6-dichloro-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (2) ◽  
pp. 379-390 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Test Substance ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Dropping Mercury Electrode ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye has been studied, a mechanism has been proposed and optimal conditions have been found for its analytical use. The detection limit using a classical dropping mercury electrode was 2 . 10-7 mol l-1 for TAST polarography and 1 . 10-8 mol l-1 for differential pulse polarography. Using a hanging mercury drop electrode, the detection limit was 9 . 10-9 mol l-1 for fast scan differential pulse voltammetry and 1 . 10-8 mol l-1 for linear scan voltammetry. Adsorption accumulation of the test substance on the surface of the hanging mercury drop electrode led to a further decrease in the detection limit to 1 . 10-9 mol l-1 for fast scan differential pulse voltammetry and 7 . 10-10 mol l-1 for linear scan voltammetry.

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