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.

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.

scholarly journals Preconcentration of Bismuth(III) and Copper(II) by Solid-Phase Extraction and Subsequent Determination by Differential Pulse Polarography

2001 ◽  
Vol 84 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Anju Bhalotra ◽  
Bal Krishan Prui
Keyword(s):  
Solid Phase ◽  
Supporting Electrolyte ◽  
Saturated Calomel Electrode ◽  
Correlation Coefficients ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Relative Standard ◽  
Microcrystalline Naphthalene

Abstract A differential pulse polarographic method is proposed for the trace determination of bismuth and copper from large volumes of aqueous samples after adsorption of their 1-(2-thiazolylazo)-2-naphthol complexes onto microcrystalline naphthalene in the pH ranges of 7.2–9.0 and 4.0–7.8, respectively. Bismuth and copper are desorbed from microcrystalline naphthalene with 9 mL 1M HCl. Well-defined peaks are obtained at Ep = −0.09 and −0.20 V versus a saturated calomel electrode, in an HCl–isoquinoline medium as the supporting electrolyte, for bismuth and copper, respectively. Bismuth is reduced reversibly with a 3-electron change, whereas copper is reduced irreversibly under these conditions. The detection limits are 55 ng/mL for bismuth and 91 ng/mL for copper. Linearity is maintained in the concentration ranges of 0.18–13.5 and 0.30-17.3 μg/mL for bismuth and copper, respectively, with corresponding correlation coefficients of 0.9996 and 0.9885. The relative standard deviations are 1.0% for bismuth at 2.0 μg/mL and 1.4% for copper at 5.0 μg/mL. Various parameters were optimized to develop conditions for the determination of these metal ions in various samples.

scholarly journals Electrochemical Analysis of Antichemotherapeutic Drug Zanosar in Pharmaceutical and Biological Samples by Differential Pulse Polarography

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Chennupalle Nageswara Reddy ◽  
Puthalapattu ReddyPrasad ◽  
NeelamYughandhar Sreedhar
Keyword(s):  
Human Urine ◽  
Supporting Electrolyte ◽  
Differential Pulse ◽  
Pharmaceutical Formulation ◽  
Urine Samples ◽  
Differential Pulse Polarography ◽  
Human Urine Samples ◽  
Pulse Polarography ◽  
Spiked Human Urine

The electrochemical reduction of zanosar was investigated systematically by direct current polarography, cyclic voltammetry, and differential pulse polarography (DPP). A simple DPP technique was proposed for the direct quantitative determination of anticancer drug zanosar in pharmaceutical formulation and spiked human urine samples for the first time. The reduction potential was −0.28 V versus Ag/AgCl with a hanging mercury drop electrode in Britton-Robinson buffer as supporting electrolyte. The dependence of the intensities of currents and potentials on pH, concentration, scan rate, deposition time, and nature of the supporting electrolyte was investigated. The calibration curve was found to be linear with the following equation:y=0.4041x+0.012, with a correlation coefficient of 0.992 (R2) over a concentration range from1.0×10-7 M to1.0×10-3 M. In the present investigation, the achieved limit of detection (LOD) and limit of quantization (LQD) were7.42×10-8 M and2.47×10-8 M; respectively. Excipients did not interfere with the determination of zanosar in pharmaceutical formulation and spiked urine samples. Precision and accuracy of the developed method were checked by recovery studies in pharmaceutical formulation and spiked human urine samples.

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.

Rapid Differential Pulse Polarographic Determination of Tiaprofenic Acid

1984 ◽  
Vol 67 (4) ◽  
pp. 684-687
Author(s):  
Mohamed E Mohamed ◽  
Abdel-Aziz M Wahbi ◽  
EL Rasheed A Gad-Kariem ◽  
Mahmoud M A Hassan
Keyword(s):  
Supporting Electrolyte ◽  
Tiaprofenic Acid ◽  
Reference Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Experimental Conditions ◽  
Tablet Form ◽  
Peak Current ◽  
Pulse Polarography

Abstract Tiaprofenic acid (Surgam®) has been determined directly by using differential pulse polarography (DPP) and pH 5.5 acetate buffer as a supporting electrolyte. The differential pulse polarogram was obtained under constant amplitude pulses of 50 mV superimposed on a linearly increasing dc ramp. Peak current was measured at the peak potential of — 0.990 V vs Ag/AgCl reference electrode. Under the experimental conditions used, a linear relationship between peak current and concentration was established over the range 0.5-5.0 ng/mL. Mean percentage recoveries for tiaprofenic acid in authentic and tablet forms were 100.27 ± 2.25 and 99.45 ± 1.44, respectively. The results obtained by the DPP method were compared with those of the spectrophotometric method used by the manufacturer for the analysis of tiaprofenic acid and its tablet form.

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 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.

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