scholarly journals Polarographic Behavior and Determination of 1,1-Dimethyl-3-phenyltriazene

2007 ◽  
Vol 72 (9) ◽  
pp. 1229-1243 ◽  
Author(s):  
Ljubiša M. Ignjatović ◽  
Jiří Barek ◽  
Jiří Zima ◽  
Dragan A. Marković
Keyword(s):  
Direct Current ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Optimum Conditions ◽  
Polarographic Behavior ◽  
Mercury Drop Electrode ◽  
Pulse Polarography

Polarographic behavior of the genotoxic substance 1,1-dimethyl-3-phenyltriazene was investigated and optimum conditions were found for its determination by sampled direct current polarography and differential pulse polarography at a static mercury drop electrode in the concentration range from 1 × 10-4 to 1 × 10-7 mol l-1. It was established that for reduction of the triazene group four electrons are required resulting in the formation of amino and hydrazo compound. The resulting products were identified, and the reduction pathway was proposed.

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 1-(2'-Nitrophenyl)-3,3-dimethyltriazene

1993 ◽  
Vol 58 (9) ◽  
pp. 2021-2038 ◽  
Author(s):  
Jiří Barek ◽  
Dana Dřevínková ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Concentration Region ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic behaviour of 1-(2'-nitrophenyl)-3,3-dimethyltriazene in mixed aqueous-methanolic solvent was investigated by tast polarography, differential pulse polarography, and fast scan differential pulse voltammetry at a hanging mercury drop electrode. A mechanism is suggested for the reduction of the compound investigated. The optimum conditions were found for the determination of this analyte by tast polarography over the concentration region of 100 to 2 μmol l-1 and by differential pulse polarography or fast scan differential pulse voltammetry at a hanging mercury drop electrode over the region of 100 to 0.2 μmol l-1. Additional sensitivity increase in the last-mentioned technique was achieved by adsorptive accumulation of analyte on the hanging mercury drop surface, owing to which the concentration region was depressed to 0.1 - 0.02 μmol l-1.

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.

Polarographic and Voltammetric Determination of 4,4'-Bis[(4-phenylamino-6-morpholino-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic Acid

1995 ◽  
Vol 60 (8) ◽  
pp. 1247-1260
Author(s):  
Jiří Barek ◽  
Roman Hrnčíř ◽  
Josino C. Moreira ◽  
Jiří Zima
Keyword(s):  
Linear Sweep Voltammetry ◽  
Differential Pulse ◽  
Disulfonic Acid ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Technical Products ◽  
Layer Chromatography

The polarographic and voltammetric behaviour of the title compound, which is the basic component in many commercial optical whitening agents, was investigated. The optimum conditions were found for the determination of the substance in dimethylformamide solutions containing 5% (v/v) water by tast polarography, differential pulse polarography, linear sweep voltammetry using a hanging mercury drop electrode, and differential pulse polarography using a hanging mercury drop electrode over the concentration regions of 100-500, 10-500, 10-500, and 1-100 mmol l-1, respectively. Practical applicability of the newly developed methods to the determination of the analyte in technical products, either direct or following separation by thin layer chromatography, was verified.

Polarographic and Voltammetric Determination of 1-Nitropyrene

2000 ◽  
Vol 65 (12) ◽  
pp. 1888-1896 ◽  
Author(s):  
Jiří Barek ◽  
Jiří Zima ◽  
Josino C. Moreira ◽  
Alexandr Muck
Keyword(s):  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Optimum Conditions ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Pulse Voltammetry ◽  
The Given

The polarographic behaviour of 1-nitropyrene was investigated by tast polarography, differential pulse polarography (both with a dropping mercury electrode), differential pulse voltammetry, and adsorptive stripping voltammetry (both with a hanging mercury drop electrode). Optimum conditions have been found for its determination by the given methods in the concentration ranges 2-100, 0.2-100, 0.1-10, and 0.001-0.01 μmol l-1, respectively.

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.

Polarographic and Voltammetric Determination of 4,4'-Bis[(4-diethanolamino-6-(2,5-disulfophenylamino)-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic Acid

1996 ◽  
Vol 61 (5) ◽  
pp. 663-672
Author(s):  
Jiří Barek ◽  
Roman Hrnčíř ◽  
Josino C. Moreira ◽  
Jiří Zima
Keyword(s):  
Linear Sweep Voltammetry ◽  
Differential Pulse ◽  
Disulfonic Acid ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Tetraethylammonium Bromide ◽  
Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Technical Products

The polarographic and voltammetric behaviour was studied for 4,4'-bis[(4-diethanolamino-6-(2,5-disulfophenylamino)-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic acid, which is the basis of many commercial optical whitening agents. The optimum conditions were found for quantitation of this substance in tetraethylammonium bromide solutions in dimethylformamide containing 5% (v/v) water using TAST polarography, differential pulse polarography, linear sweep voltammetry at a hanging mercury drop electrode, and differential pulse voltammetry at a hanging mercury drop electrode over the concentration regions of 100-500, 10-500, 10-500, and 1-100 mmol l-1, respectively. The practical applicability of the new analytical methods to the determination of the substance in technical products was verified.

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.

Polarographic Determination of 4'-Substituted Derivatives of 3-Carboxy-4-hydroxy-6-acetylaminoazobenzene

1994 ◽  
Vol 59 (11) ◽  
pp. 2397-2414 ◽  
Author(s):  
Jiří Barek ◽  
Piero Savarino ◽  
Lucie Stuchlíková ◽  
Jiří Zima
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Reduction Mechanism ◽  
Optimum Conditions ◽  
Entire Series ◽  
Pulse Polarography ◽  
Half Wave ◽  
Hammett Σ Constants ◽  
Derivatives Of

Tast polarography, differential pulse polarography and cyclic voltammetry were applied to the examination of 7 derivatives of 3-carboxy-4-hydroxy-6-acetylaminoazobenzene with H, CH3, OCH3, Cl, COCH3, NO2 and NHCOCH3 substituents in position 4'. A general reduction mechanism was suggested for the substances. The half-wave potentials obtained from tast polarographic measurements were correlated with the Hammett σ constants of the substituents in the para-position. The plot of this dependence is linear, which suggests that the reduction mechanism is identical within the entire series. The optimum conditions for quantitation of the substances were found within the concentration regions of 1 .10-4 to 1 .10-6 mol l-1 for tast polarography and 1 .10-4 to 1 .10-7 mol l-1 for differential pulse polarography.

Sign in / Sign up

Export Citation Format

Share Document