The polarographic and voltammetric determination of semitrypane blue

1989 ◽  
Vol 54 (6) ◽  
pp. 1538-1548
Author(s):  
Jiří Barek ◽  
Ashutosh Ghosh ◽  
Jiří Zima

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.

2004 ◽  
Vol 69 (11) ◽  
pp. 2021-2035 ◽  
Author(s):  
Kumaran Shanmugam ◽  
Jiří Barek ◽  
Jiří Zima

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.


1993 ◽  
Vol 58 (2) ◽  
pp. 295-309 ◽  
Author(s):  
Jiří Barek ◽  
Dana Dřevínková ◽  
Viktor Mejstřík ◽  
Jiří Zima

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.


1988 ◽  
Vol 53 (5) ◽  
pp. 921-928
Author(s):  
Jiří Barek ◽  
Janina Balsiene ◽  
Barbara Tietzová ◽  
Jiří Zima

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.


1987 ◽  
Vol 52 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová

The polarographic reduction of the title azodye has been studied, a mechanism has been proposed for this process and conditions have been found for the determination of this substance by TAST polarography, with a detection limit of 7 . 10-7 mol l-1, differential pulse polarography at a dropping mercury electrode with a detection limit of 3.5 . 10-7 mol l-1, fast scan differential pulse voltammetry at a static mercury drop electrode with a detection limit of 6.9 . 10-9 mol l-1 and voltammetry with linearly increasing voltage at a hanging mercury drop with a detection limit of 1.6 . 10-9 mol l-1.


1990 ◽  
Vol 55 (2) ◽  
pp. 379-390 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima

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.


2011 ◽  
Vol 76 (12) ◽  
pp. 1775-1790 ◽  
Author(s):  
Andrea Hájková ◽  
Vlastimil Vyskočil ◽  
Aleš Daňhel ◽  
Joseph Wang ◽  
Jiří Barek

Electrochemical behavior of genotoxic 2-aminofluoren-9-one (2-AFN) was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a classical dropping mercury electrode (DME), and by DC voltammetry (DCV), differential pulse voltammetry (DPV), and adsorptive stripping differential pulse voltammetry (AdSDPV), all at a miniaturized hanging mercury drop minielectrode (HMDmE), in buffered aqueous-methanolic solutions. Optimum conditions were found for the determination of 2-AFN by DCTP at DME in the concentration range from 1 × 10–6to 1 × 10–4mol l–1(with a limit of quantification (LQ) of 5 × 10–7mol l–1), by DPP at DME (from 1 × 10–7to 1 × 10–4mol l–1;LQ ≈ 1 × 10–7mol l–1), by DCV and DPV at HMDmE (both from 1 × 10–7to 1 × 10–4mol l–1;LQs ≈ 2 × 10–7and 1 × 10–7mol l–1for DCV and DPV, respectively), and by AdSDPV at HMDmE (from 2 × 10–9to 1 × 10–7mol l–1;LQ ≈ 4 × 10–9mol l–1). Practical applicability of the developed methods was verified on the direct determination of 2-AFN in model samples of drinking and river water in nanomolar to micromolar concentrations.


1987 ◽  
Vol 52 (4) ◽  
pp. 867-877
Author(s):  
Jiří Barek ◽  
Barbara Tietzová ◽  
Jiří Zima

The polarographic reduction of the bisazodye congo red has been studied, a mechanism was proposed for this process and optimal conditions were found for determination of this substance by TAST polarography and differential pulse polarography at a dropping mercury electrode and using fast scan differential pulse voltammetry and voltammetry with linearly increasing voltage at a hanging mercury drop electrode. The detection limit for the latter two techniques is about 10-8 mol l-1; a further decrease in the value can be attained by prior accumulation of the determined substance by adsorption on the surface of the working electrode.


1990 ◽  
Vol 55 (12) ◽  
pp. 2904-2913 ◽  
Author(s):  
Jiří Barek ◽  
Jana Kubíčková ◽  
Viktor Mejstřík ◽  
Oldřich Petira ◽  
Jiří Zima

The polarographic reduction of the 3'-halogen derivatives of N,N-dimethyl-4-aminoazobenzene was studied in mixed water-methanol medium and optimum conditions were found for the determination of these genotoxic substances by tast polarography in the concentration range 1 . 10-4 to 2 . 10-6 mol l-1, differential pulse polarography at a dropping mercury electrode in the range 1 . 10-4 to 2 . 10-7 mol l-1 and fast scan differential pulse voltammetry at a hanging mercury drop electrode in the range 1 . 10-6 to 2 . 10-8 mol l-1. The increase in the sensitivity resulting from adsorptive accumulation of the studied substances on the surface of a hanging mercury drop can be utilized in the determination using the latter method in the concentration range 1 . 10-8 to 2 . 10-9 mol l-1.


1992 ◽  
Vol 57 (11) ◽  
pp. 2263-2271
Author(s):  
Jiří Barek ◽  
Jana Kubíčková ◽  
Viktor Mejstřík ◽  
Jiří Zima

A study was made of the polarographic reduction of the title triazene, a mechanism was proposed for this process and optimal conditions were found for its analytical application using tast polarography in the range 1 . 10-4 - 2 . 10-6 mol l-1, differential pulse polarography in the range 1 . 10-4 - 2 . 10-7 mol l-1 and fast scan differential pulse voltammetry at a hanging mercury drop electrode in the range 1 . 10-4 - 2 . 10-7 mol l-1. The sensitivity of the latter technique was increased through adsorptive accumulation of the test substance on the surface of the working electrode, permitting determination in the concentration range 1 . 10-7 - 2 . 10-9 mol l-1.


1988 ◽  
Vol 53 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Jiří Barek ◽  
Jana Balsiene ◽  
Antonín Berka ◽  
Ivana Hauserová ◽  
Jiří Zima

The polarographic reduction of the title azo dye was studied, a mechanism was suggested and optimal conditions were determined for analytical utilization of this process. A detection limit of 3 . 10-7 mol 1-1 was obtained using fast scan differential pulse voltammetry and 0.7 . 10-7 mol 1-1 using linear potential scan voltammetry at a hanging mercury drop electrode. The detection limit can be decreased by adsorptive accumulation of the determined substance on the surface of the hanging mercury drop electrode, to 1 . 10-8 mol 1-1 for fast scan differential pulse voltammetry and 0.6 . 10-8 mol 1-1 for linear scan voltammetry. The selectivity of the determination can be improved by preliminary separation by extraction or thin-layer chromatography.


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