Analysis of mixtures of 4-nitrotoluene-2-sulphonic acid and 4,4'-dinitrostilbene-2,2'-disulphonic acid by tast polarography, differential pulse polarography and thin layer chromatography

1985 ◽  
Vol 50 (8) ◽  
pp. 1673-1684
Author(s):  
Jiří Barek ◽  
Ivo Daňhel
Keyword(s):  
Thin Layer ◽  
Differential Pulse ◽  
Sulphonic Acid ◽  
Polarographic Determination ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Tetramethylammonium Bromide ◽  
Disulphonic Acid ◽  
Layer Chromatography

Conditions are sought for the determination of 4-nitrotoluene-2-sulphonic acid (I) and 4,4'-dinitrostilbene-2,2'-disulphonic acid (II) by TAST polarography within the concentration range of 10-2 - 10-6 mol l-1 and by differential pulse polarography (DPP) within the concentration range of 10-3 - 10-8 mol l-1. DPP is applied to the determination of these substances after the thin layer chromatographic separation of their mixtures. Methods are also worked out for their analysis without prior separation, based either on the combined DPP determination of I and the TAST polarographic determination of the sum of I and II in sulphuric acid solutions, or on the DPP determination of the C=C bond in II and the TAST polarographic determination of the sum of the two substances in tetramethylammonium bromide solutions.

scholarly journals DIFFERENTIAL PULSE POLAROGRAPHIC DETERMINATION OF ARSENIC IN BITUMINOUS COAL

1998 ◽  
Vol 6 (7) ◽  
pp. 27-32
Author(s):  
M. Nogami Eurica ◽  
M. Dalmeida Gracinda ◽  
Jorge Nozaki
Keyword(s):  
Coal Sample ◽  
Bituminous Coal ◽  
Supporting Electrolyte ◽  
Arsenic Concentration ◽  
Differential Pulse ◽  
Polarographic Determination ◽  
Differential Pulse Polarography ◽  
Acidic Media ◽  
Pulse Polarography

Differential pulse polarography was employed for the determination of arsenic in bituminous coal from Figueiras, Parana, Brazil. The dried coal sample was crushed to -100 mesh, ashed, and treated with reducing reagents in acidic media. The arsine generated was collected and selectively oxidized to Al +3 using an absorbing solution of 0.1 mol.L -1 [tris(hydroxymethyl) aminomethane] ( TRIS) and 0. 002 mol.L -1 silver nitrate. A solution of TRIS and hydrochloric acid, pH -1, was used as supporting electrolyte for differential pulse polarographic determination of Al+3 in the concentration range 0.05 -0.60 μglmL. The average arsenic concentration found was 69.0 ± 2.6 mg.kg -1 and was in agreement with the spectrophotometric method using silver-diethyldithiocarbamate-pyridine.

The polarographic and voltammetric determination of 5-(3-phenoxysulphenylazo)-6-hydroxy-3-cyano-1,4-dimethyl-2-pyridone

1989 ◽  
Vol 54 (8) ◽  
pp. 2105-2119 ◽  
Author(s):  
Jiří Barek ◽  
Ivana Švagrová-Hauserová ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Layer Chromatography

The polarographic reduction of the title azodye has been studied, a mechanism was proposed and optimal conditions were found for the determination of this substance by TAST polarography in the range 5.10-5-2.10-6 mol l-1 and differential pulse polarography at a dropping mercury electrode in the range 5.10-5-2.10-8 mol l-1. The sensitivity was further increased by adsorptive accumulation of the determined substance on the surface of a hanging mercury drop electrode with linear scan voltammetry (determination limit 5.10-10 mol l-1). The selectivity was increased by prior separation of the determined azodye using thin layer chromatography and by transferring the substance adsorbed on the surface of the hanging mercury drop to a new base electrolyte solution.

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 Determination of 7-Diethylamino-4-methylcoumarin

1995 ◽  
Vol 60 (5) ◽  
pp. 802-812
Author(s):  
Jiří Barek ◽  
Roman Hrnčíř ◽  
Josino C. Moreira
Keyword(s):  
Mercury Electrode ◽  
Differential Pulse ◽  
Polarographic Determination ◽  
Differential Pulse Polarography ◽  
Whitening Agent ◽  
Polarographic Behaviour ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Technical Products

The polarographic behaviour of the title optical whitening agent was studied in aqueous-methanolic solutions. Conditions for its quantitation were found within the concentration regions of 10 to 100 μmol l-1 by tast polarography, 1 to 100 μmol l-1 by differential pulse polarography on the conventional dropping mercury electrode, and 0.1 to 10 μmol l-1 by differential pulse polarography on a static mercury drop electrode. The analytical procedures developed were applied to the determination of the compound in technical products.

The polarographic and voltammetric determination of N,N-dimethyl-4-amino-3'-methylazobenzene

1987 ◽  
Vol 52 (9) ◽  
pp. 2149-2159 ◽  
Author(s):  
Jiří Barek ◽  
Tibor J. Pastor ◽  
Simona Votavová ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Pulse Polarography ◽  
Practical Usefulness ◽  
Dropping Mercury Electrode ◽  
Pulse Voltammetry ◽  
Layer Chromatography

The polarographic reduction of N,N-dimethyl-4-amino-3'-methylazobenzene has been studied, a mechanism has been proposed and conditions have been found for the determination of this depolarizer using TAST polarography and differential pulse polarography at a classical dropping mercury electrode and using fast scan differential pulse voltammetry and linear scan voltammetry at a hanging mercury drop electrode. The detection limit at this electrode is about 10-8 mol l-1; a further decrease can be attained using adsorption accumulation of the determined azo-substance on the surface of the working electrode. In conclusion, the practical usefulness of these methods combined with extraction or thin-layer chromatography was verified.

The Polarographic Determination of 1-[4'-(Phenylazo)phenyl]-3,3-dimethyltriazene

1992 ◽  
Vol 57 (11) ◽  
pp. 2248-2262 ◽  
Author(s):  
Jiří Barek ◽  
Dana Dřevínková ◽  
Jiří Zima ◽  
Arnold Fogg
Keyword(s):  
Differential Pulse ◽  
Polarographic Determination ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Optimal Conditions ◽  
Polarographic Behaviour ◽  
Pulse Polarography ◽  
Methanol Medium ◽  
Mixed Water

A study has been made of the polarographic behaviour of genotoxic 1-[4'-(phenylazo)phenyl]-3,3-dimethyltriazene in mixed water-methanol medium. 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 1 . 10-4 - 2 . 10-6 mol l-1 and using differential pulse polarography in the concentration range 1 . 10-4 - 2 . 10-7 mol l-1.

Polarographic determination of some nitro group-containing pesticides

1983 ◽  
Vol 48 (9) ◽  
pp. 2636-2643 ◽  
Author(s):  
Hana Beňadiková ◽  
Milan Popl ◽  
Věra Jakubíčková
Keyword(s):  
Nitro Group ◽  
Supporting Electrolyte ◽  
Differential Pulse ◽  
Environmental Water ◽  
Polarographic Determination ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Water Purity

The differential pulse polarography technique was applied to the determination of some pesticides containing nitro groups in their molecules. The nitro groups were found to be reduced to hydroxylamines or to the corresponding amines. The effect of medium, particularly of pH of the supporting electrolyte, was examined. The pesticides were determined in concentrations less than 10 μg l-1, which shows primose for the application of the technique to environmental water purity monitoring.

Determination of platinum in biological material by differential pulse polarography: Analysis in urine, plasma and tissue following sample combustion

1983 ◽  
Vol 48 (10) ◽  
pp. 2903-2908 ◽  
Author(s):  
Viktor Vrabec ◽  
Oldřich Vrána ◽  
Vladimír Kleinwächter
Keyword(s):  
Biological Material ◽  
Biological Fluid ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Linear Calibration ◽  
Catalytic Current ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

A method is described for determining total platinum content in urine, blood plasma and tissues of patients or experimental animals receiving cis-dichlorodiamineplatinum(II). The method is based on drying and combustion of the biological material in a muffle furnace. The product of the combustion is dissolved successively in aqua regia, hydrochloric acid and ethylenediamine. The resulting platinum-ethylenediamine complex yields a catalytic current at a dropping mercury electrode allowing to determine platinum by differential pulse polarography. Platinum levels of c. 50-1 000 ng per ml of the biological fluid or per 0.5 g of a tissue can readily be analyzed with a linear calibration.

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