ISSN 2738-0971 | eISSN 2738-1013
Bulletin of Natural Sciences Research
Open access journal | Double-blind peer review

Ranko Simonović

Faculty of Natural Sciences and Mathematics, University of Priština, Kosovska Mitrovica

Articles

Open Access Original Scientific Paper

KINETIC-CATALYTIC DETERMINATION OF ULTRAMICRO AMOUNTS OF Co(II) USING 4-HYDROXYCOUMARINE-PERMANGANATE REDOX REACTION

by Dragana Sejmanović, Ružica Micić, Ranko Simonović

Determination of Co(II) based on its catalytic effect on the reaction between 4-hydroxycoumarine and potassium permanganate, in the presence of acetate buffer was described. The method development includes optimization of the reagent concentration and temperature. Absorbance of potassium permanganate was measured at 525 nm. The calibration curve was linear in the range of 0.5 - 4 ng/cm3 of Co(II). The relative standard deviation was in the interval 6.25-2.60 % of the concentration range of 0.6-3 ng/cm3 Co(II), respectively. The interference effects of foreign ions were determined for the assessment of the selectivity of the method. The proposed method was found to have excellent sensitivity, relatively good selectivity and simplicity.

View Full-Text DOI 10.5937/univtho8-16036 Published: 26 Mar 2018
Open Access Original Scientific Paper

KINETIC DETERMINATION OF GOLD(III) BASED ON ITS INHIBITORY EFFECT IN OXIDIZING HOMOGENOUS REACTION SYSTEM

by Ružica Micić, Snežana Mitić, Ranko Simonović, Dragana Sejmanović

Development and application of a simple, fast, green analytical kinetic method for the determination of micro-amounts of gold(III ) ions, were presented in this paper. The method was based on the inhibitory effect of traces of Au(III) ions on the redox reaction between disodium-6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphtalenesulfonate (artificial azo-dye "Sunset Yellow FCF", E110 in further text selected as SY ) and hydrogen-peroxide, in alkaline media of borate buffer. All experimental parameters affecting to the determination: reagent concentrations, pH and temperature were investigated and optimised. Working experimental conditions are set according to the highest sensitivity of the proposed kinetic method for the determination of Au(III) ions. The linearity of the method was obtained within the range 1.97-59.07 μg/mL of Au(III) ions with relative standard deviation of 3.66- 0.43 %, respectively. The influence by possible interference effects by major ions on the determination of Au(III) and their limits are investigated, at the constant Au(III) concentration of 39.39 μg/mL. The results of Au(III) determination in samples obtained by proposed kinetic method and comparative ICP-OES method were statistically agreeable. Obtained results for Au(III) determination in analyzed samples, as well as the development and validation of the proposed analytical procedure have given and discussed.

View Full-Text DOI 10.5937/univtho6-11894 Published: 31 Dec 2016
Open Access Original Scientific Paper

A SENSITIVE KINETIC SPECTROPHOTOMETRIC DETERMINATION OF TRACES OF TUNGSTEN IN SOLUTION BASED ON ITS INHIBITORY EFFECT ON THE DECOLORIZATION REACTION OF POTASSIUM PERMANGANATE

by Branka Petković, Ružica Micić, Ranko Simonović

The present work describes a rapid and sensitive method for the determination of ultramicro amounts of tungsten (VI) based on its inhibitory effect on the oxidation of 4-hidroxycoumarine by potassium permanganate in the presence of hydrochloric acid. The sensitivity of the method is 20 ng/cm3. The probable relative error is -4.8-13 % for the W(VI) concentration range 250 to 20 ng/cm3, respectively. Kinetic equations for the investigated process which determine the order of the reactions regarding to each reaction parameter under certain experimental conditions were proposed, and they allowed quantification of the unknown concentrations W(VI) in solution. The detection and quantification limit of the method are 4.5 and 15.1 ng/cm3. The effects of certain foreign ions upon the reaction rate were determined for the assessing the selectivity of the method.

View Full-Text DOI 10.5937/univtho6-10437 Published: 22 Jun 2016