Determination of chromium(VI) by differential-pulse polarography with a sodium fluoride supporting electrolyte

The Analyst ◽  
1984 ◽  
Vol 109 (7) ◽  
pp. 927 ◽  
Author(s):  
James A. Cox ◽  
Janice L. West ◽  
Pawel J. Kulesza
Keyword(s):  
Sodium Fluoride ◽  
Supporting Electrolyte ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Chromium Vi ◽  
Pulse Polarography

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.

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 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.

Polarography of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol mixtures

1985 ◽  
Vol 50 (3) ◽  
pp. 712-725 ◽  
Author(s):  
Jiří Barek ◽  
Lubomír Kelnar
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Reduction Mechanism ◽  
Pulse Polarography ◽  
Methanol Medium

The polarographic reduction of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol medium was investigated. Evidence is presented for adsorption of the depolarizer on the electrode, and a reduction mechanism is proposed. Conditions are indicated for the determination of this compound in the concentration range 10-4-10-6 mol/l by d.c. polarography, 10-5 to 3 . 10-7 mol/l by Tast polarography, and 10-5-3 . 10-8 mol/l by differential pulse polarography.

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.

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