scholarly journals Analysis of trace elements in Turkish raki by differential pulse polarography

2021 ◽  
pp. ArticleID:210932
Author(s):  
Sukru Kalayci ◽  
Author(s):  
Sukru Kalayc ◽  
Guler Somer

In this work a new and simple polarographic method has been established for the determination of trace elements present in tea. After digestion with acids, tea samples were analyzed using various electrolytes such as acetate and ammonia at different pH values in the presence or absence of EDTA. Thus, it was possible tochoosethe best medium for the determination of6 trace elements in one tea sample. Polarographic peaks of copper and iron could be separated in HAc at about pH =7 in the presence of EDTA and their quantities were determined. Ni and Zn peaks could be separated and determined in ammonia buffer at about pH= 10. Lead could be determined at pH= 2HAc electrolyte. Selenite, was determined from its hydrogen catalytic peak in KCl, pH= 2 medium in the presence of Mo (VI). The LOD was found as 2.4x10-7 for instead of (S/N=3).The trace element ranges in black tea were found as, Fe 35 μg/g, Cu 45 μg/g, Ni 19 μg/g, Zn  22 μg/g, Pb 28 μg/g and Se 77  μg/g.


2003 ◽  
Vol 81 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Güler Somer ◽  
Gülbeniz Guliyeva ◽  
Güler Ekmekci ◽  
Olcay Sendil

A fast and simple method was established for the determination of trace elements in liver. DP polarograms of wet digested liver samples were taken in acetate buffer, pH about 4, for lead, cadmium, and zinc determinations. For copper, addition of EDTA at pH 4 was needed for a better separation from the iron peak. Selenite ion was determined using the hydrogen catalytic peak after the addition of Mo(VI) to the same solution. Trace element levels were different for two separate sections of liver. For the first section (S1) the quantities were found to be 8.12 ± 0.21 mg g–1 Cu, 1.16 ± 0.12 mg g–1 Zn, 1.09 ± 0.11 mg g–1 Cd, 0.59 ± 0.07 mg g–1 Pb, and 2.05 ± 0.22 mg g–1 Se, in dry liver. For the second section (S2) the results were the same for selenium, but Cd was too small to be detected. The other trace element quantities were 0.48 mg g–1 Cu, 0.22 mg g–1 Pb, and 0.29 mg g–1 zinc. The validity of the method was demonstrated with a synthetic sample resembling liver composition. This method enabled the simultaneous determination of heavy trace elements such as copper, lead, cadmium, molybdenum, selenium, and zinc by using an inexpensive instrument and without any separation or pre-concentration procedures.Key words: cow liver, determination, differential pulse polarography, trace elements.


1983 ◽  
Vol 48 (10) ◽  
pp. 2903-2908 ◽  
Author(s):  
Viktor Vrabec ◽  
Oldřich Vrána ◽  
Vladimír Kleinwächter

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.


1985 ◽  
Vol 50 (3) ◽  
pp. 712-725 ◽  
Author(s):  
Jiří Barek ◽  
Lubomír Kelnar

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.


1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima

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.


1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima

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.


1991 ◽  
Vol 56 (7) ◽  
pp. 1434-1445 ◽  
Author(s):  
Jiří Barek ◽  
Ivana Švagrová ◽  
Jiří Zima

Polarographic reduction of the genotoxic N,N’-dinitrosopiperazine was studied and its mechanism was suggested. Optimum conditions were established for the determination of this substance by tast polarography over the concentration region of 1 . 10-3 to 1 . 10-6 mol l-1 and by differential pulse polarography on the conventional dropping mercury electrode or by fast scan differential pulse voltammetry and linear sweep voltammetry on a hanging mercury drop electrode over the concentration region of 1 . 10-3 to 1 . 10-7 mol l-1. Attempts at increasing further the sensitivity via adsorptive accumulation of the analyte on the surface of the hanging mercury drop failed. The methods are applicable to the testing of the chemical efficiency of destruction of the title chemical carcinogen based on its oxidation with potassium permanganate in acid solution.


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