Some remarks concerning polarographic determination of sulphur-containing herbicides

1984 ◽  
Vol 49 (5) ◽  
pp. 1282-1288 ◽  
Author(s):  
Věra Stará ◽  
Miloslav Kopanica
Keyword(s):  
Differential Pulse Voltammetry ◽  
Concentration Dependence ◽  
Acidic Medium ◽  
Differential Pulse ◽  
Hanging Mercury Drop Electrode ◽  
Voltammetric Curve ◽  
Buffer Solution ◽  
Peak Current ◽  
Pulse Voltammetry

The herbicide methomyl (2-methylthio-propionaldehyde-o-methylcarbamoyloxime) can be determined using fast scan differential pulse voltammetry with hanging mercury drop electrode by the measurement of the peak at -1.30 V (S.C.E.) which caused by the presence of methomyl in the ammoniacal buffer solution containing cobalt(II) salt. The peak current vs methomyl concentration dependence is linear over the concentration range 0.5 to 20.0 μg . l-1. The herbicide aldicarb (2-methyl-2(methylthio)propionaldehyde-o-methylcarbamoyloxime) is determined by its influence on the differential pulse voltammetric curve of copper(II) recorded in electrochemically enriched solution in acidic medium. The corresponding peak current at the potential + 0.08 V (S.C.E.) depends linearly on the aldicarb concentration in the range 0.07 to 5.00 μg ml-1.

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The voltammetric determination of 4-nitrobiphenyl

1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Working Electrode ◽  
Pulse Voltammetry ◽  
Unstirred Solution

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

Differential Pulse Voltammetry Method for the Determination of Glucose on Multi-Nanostructured Active Electrode Modified by Platinum Nanoparticles

2012 ◽  
Vol 554-556 ◽  
pp. 440-444
Author(s):  
He Zhen Wu ◽  
Aie Cao ◽  
Di Lou Xu ◽  
Dao Bao Chu
Keyword(s):  
Differential Pulse Voltammetry ◽  
Platinum Nanoparticles ◽  
Glucose Concentration ◽  
Differential Pulse ◽  
Oxidation Peak ◽  
Active Electrode ◽  
Peak Current ◽  
Oxidation Peak Current ◽  
Pulse Voltammetry

Electrocatalytic oxidation of multi-nanostructured active electrode modified by platinum nanoparticles on glucose was examined. Based on 0.5mol/L KOH solution, we see a sensitive and good-shaped oxidation peak current near -0.77V (VS, SCE) by using differential pulse voltammetry method to scan in the range of -0.9~0.4V.The peak is regarded as the quantitative peak. There is a good linear relationship between glucose concentration and the peak current in the range of 1.0×10-2~1.0×10-5 mol/L. The linear correlation coefficient is 0.99864.The detection limit is 1.0×10-6mol/L. If added 0.06 m mol/L ascorbic acid or 0.3m mol/L uric acid (simulating human blood components), the determination of glucose is not interfered with. Results of the determination of glucose concentration in the blood are satisfactory.

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

1992 ◽  
Vol 57 (11) ◽  
pp. 2263-2271
Author(s):  
Jiří Barek ◽  
Jana Kubíčková ◽  
Viktor Mejstřík ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Test Substance ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

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.

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.

Voltammetric determination of 6-nitrobenzimidazole in the presence of surfactants

2011 ◽  
Vol 76 (11) ◽  
pp. 1317-1325 ◽  
Author(s):  
Dana Deýlová ◽  
Jiří Barek ◽  
Vlastimil Vyskočil
Keyword(s):  
Differential Pulse Voltammetry ◽  
Cetyltrimethylammonium Bromide ◽  
Sodium Dodecyl ◽  
Differential Pulse ◽  
Hanging Mercury Drop Electrode ◽  
Silver Solid Amalgam Electrode ◽  
Amalgam Electrode ◽  
Pulse Voltammetry ◽  
Triton X

Determination of 6-nitrobenzimidazole by differential pulse voltammetry at a hanging mercury drop electrode, a polished silver solid amalgam electrode and a mercury meniscus modified silver solid amalgam electrode was studied in the presence of the surfactants Triton X-100, cetyltrimethylammonium bromide and sodium dodecyl sulfate. It was found that only cetyltrimethylammonium bromide at polished silver solid amalgam electrode increases the voltammetric signal. This fact was used for the determination of 6-nitrobenzimidazole in the concentration range from 1 × 10–7 to 1 × 10–4 mol l–1 by differential pulse voltammetry at polished silver solid amalgam electrode in the presence of cetyltrimethylammonium bromide (concentration 1 × 10–4 mol l–1).

The polarographic and voltammetric determination of 2-amino-5-sulphoamoylnaphthalene-azo-(2’-chloro-4’-nitrobenzene)

1988 ◽  
Vol 53 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Jiří Barek ◽  
Jana Balsiene ◽  
Antonín Berka ◽  
Ivana Hauserová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Linear Potential ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Pulse Voltammetry ◽  
Layer Chromatography

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.

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 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.

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