Electrochemical investigation of ternary complexes of Cd(II) with some amino acids (α-alanine and β-alanine) and citrate anions

1991 ◽  
Vol 56 (6) ◽  
pp. 1193-1199 ◽  
Author(s):  
Hamada M. Killa ◽  
El-Sayed M. Mabrouk ◽  
Mohamed M. Ghoneim
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ternary Systems ◽  
Differential Pulse ◽  
Ternary Complexes ◽  
Differential Pulse Polarography ◽  
Diffusion Controlled ◽  
Pulse Polarography ◽  
The Stability ◽  
And Diffusion

The ternary complexes of Cd(II) with citrate anions as a primary ligand and amino acids (α-alanine and β-alanine) as a secondary ligand have been investigated using differential pulse polarography. Formation of three mixed complexes, [Cd(amino acid)(citrate)2] and [Cd(amino acid)2(citrate)] is observed in each case. The stability constants and the mixing constants of the ternary system have been calculated, as well as the stabilization constants. The electrochemical reduction was reversible and diffusion controlled. The various equilibria involved in the ternary systems are also given.

Differential pulse polarographic studies on simple and mixed ligand complexes of Cd(II) with diaminopropane and adipate ligands

1990 ◽  
Vol 55 (10) ◽  
pp. 2381-2389
Author(s):  
Hamada M. Killa ◽  
El-Sayed M. Mabrouk ◽  
Abdel Fattah A. Abdel Fattah
Keyword(s):  
Differential Pulse ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Mixed Complexes ◽  
Diffusion Controlled ◽  
And Diffusion ◽  
Secondary Ligand

The composition, stability and equilibria of ternary complexes of Cd(II) with adipate (Adp) as primary ligand and 1,3-diaminopropane (DAMP) as secondary ligand have been studied using differential pulse (d.p.) polarography. The results reveal the presence of three ternary complexes with stoichiometries 1:1:1, 1:1:2, and 1:2:1. Also, the composition and stability of binary species have been determined. The reduction of simple and mixed ligand complexes is reversible and diffusion controlled. The formation constants of mixed complexes were calculated and compared with the observed values.

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.

The polarographic and voltammetric determination of 2,6-dicyano-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Azo Dye ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.

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