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Bulletin of the Chemists and Technologists of Bosnia and Herzegovina

Issue 38

Publication date: July 2012

Full version of Bulletin

Table of contents

Three novel 4-methylcoumarin derivatives Original Scientific Article

Ćavar Sanja, Kovač Franci

Abstract: Substituted 4-methylcoumarins are synthesized from phenols and ethyl acetoacetate via Pechmann condensation, then, using common method for benzoylation, three novel coumarin derivatives were obtained: 4-methyl-2-oxo-2H-chromen-6-yl benzoate (2a), 4,5-dimethyl-2-oxo-2H-chromen-7-yl benzoate (2b), and 4-methyl-2-oxo- 2H-chromen-7,8-diyl benzoate (2c). The structures of novel coumarins were characterized by elemental analysis, GC/MS, NMR, and IR techniques.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 1-4.

High-order above-threshold ionization and high-order harmonic generation of molecule: a way of its characterization Original Scientific Article

Gazibegović-Busuladžić Azra, Hasović Elvedin, Odžak Senad, Busuladžić Mustafa, Milošević B. Dejan

Abstract: We investigate high-order above-threshold ionization (HATI) and high-order harmonic generation (HHG) of diatomic molecules having different symmetries by a strong laser field using modified molecular strong-field approximation. We present our results for N₂, O₂, H₂, and Ar₂ molecules. Their initial highest occupied molecular orbitals are characterized by 3σg, 1πg, 1σg, and 5σ usymmetry, respectively. By analyzing HATI and HHG spectra for different molecular orientation with respect to the laser polarization axis, and for different values of the electron or photon energies and electron emission angle, we are able to draw some conclusions about the molecular structure. The most noticeable feature of all molecular spectra is the existence of minima that are absent in the atomic case.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 5-12.

Comparison of x-ray fluorescent analysis and cupellation method for determination of gold in gold jewellery alloy Original Scientific Article

Jotanović Aida, Memić Mustafa, Suljagić Šemsa, Huremović Jasna

Abstract: To make jewellery of gold, gold is alloyed with other metals. It is of great importance to accurately determine the total amount of pure gold in alloys used for making the jewellery and in jewellery made of gold, because it determines its value on the market. Several analytical methods are used for this purpose. This study was based on comparison of results of analysis of gold alloy for 14-carat jewellery obtained by non-destructive fluorescent analysis method and destructive cupellation method. The null hypothesis with 95% confidence level on equivalence in measurement precision of perecnt by percent mass of gold in three very similar gold alloy samples in reproducibility condition (three measurement series) for standard cupellation method and the method compared (validated), XRF method, has been confirmed. F-test did not confirm null hypothesis on precision equivalence for two mentioned analysis methods. There is a significant difference in variance values. However, the t-test was carried out, which verified the null hypothesis on equivalence between mean values of results achieved in two compared values. In order to confirm applicabilty of two methods, Z score was calculated giving values of less than 2, using statistical data from inter-laboratory program with 62 participating laboratories applying cupellation method, and 60 laboratories applying XRF method for analysis of gold alloy used in production of 14-carat jewellery.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 13-18.

Electrochemical characteristics of welded joints on stainless steel in maritime atmosphere Original Scientific Article

Korać Fehim, Gutić Sanjin, Semić Inesa, Kozica Indira, Gojak Sabina, Islamović Safija, Ostojić Jelena

Abstract: Maritime atmosphere represents the corrosion environment characterized by air saturated with chloride. Many different factors affect the quality of welded joint and the material around it. In case of welding of steel structures, those factors include selection of the welding process, an additional electrode material, and type of lining. Stainless steel is used for different equipment that is exposed to sea water. Connecting those parts together is done by welding method whose quality depends on a number of factors. Some of those factors are investigated in this study. Samples used in experiments are X5CrNi 18-10ASTMAISI304 stainless steel sheets of austenitic type. This sheet is welded in two different ways: manual arc welding in a protective atmosphere of argon and manual arc welding with covered rutile electrode. Corrosion characteristics have been investigated for three distinct zones: zone of welded joint itself, zone in the vicinity of welded joint and zone far from welded joint (basic material). Tests were performed in 0.9% and 3% NaCl solution, as well as in sea water samples from the area of Dubrovnik and Ploče (brackish water). Electrochemical study has been performed by means of potentiodynamic polarization between -0,150V and 0,350V vs. saturated Ag/AgCl electrode. Results obtained for X5CrNi18-10 austenitic steel and its welded parts in different media at room temperature indicate some degree of self-passivation along with uniform corrosion processes. Based on the obtained results, we concluded that values of corrosion potential lie between 0.350V and -0.150V, depending on the environment in which each sample is probed. In the case of sample welded with dross, increase of corrosion rate does not follow increment of chloride concentration in the expected extent. Corrosion processes are mostly located on the ZUT-OM interface. For the majority of samples, welding in argon atmosphere proved to be a more acceptable way of processing metals from the aspect of corrosion resistance.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 19-24.

Structure of blue copper proteins: electron-transfer kinetics of Cu(II/I) copper complex with macrocylic ligand with N2S2 donor set Original Scientific Article

Galijašević Semira

Abstract: In electron-transfer, the change in the oxidation state of the reactants is generally accompanied by structural changes, which influence the electron-transfer kinetics. Previous studies on the systems of Cu(II/I) complexes involving cyclic tetrathiaether ligands indicated that inversion of coordinated donor atoms may be a primary factor in controlling gated electron transfer. Complex formation and isopmerization studies on [14]aneN4 type complexes have demonstrated that coordinated N atoms are shown to invert since they must undergo a hydrogen abstraction prior to inversion. In the systems with [14]aneNxS4-x ligands, there is a choice of N or S inversion. This study has been conducted to determine the effect of inversion of coordinated N atoms on electron-transfer rates as a function of different concentrations of water as hydrogen ion acceptor existing in aprotic solvent (acetonitrile). Data on electron-transfer kinetics are presented here. Possible conformational changes and kinetics pathways for N-S mixed donor complexes are discussed.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 25-30.

Determination of mercury in the urine by atomic absorption spectrometry – cold vapor technique Original Scientific Article

Kešeljević Bojan, Huremović Jasna,Sulejmanović Jasmina

Abstract: Urine is a liquid waste product of the body. Substances that are ingested and fail to be apsorbed are excreted, solid waste through the intestines, the urine through the kidney and ureter and another fluid from the body through perspiration. Determination of mercury content of urine is not included in routine examinations, but mercury can be present in urine at concentrations that could have serious effects on human health. Urine donors were selected in regard to their occupations, age, lifestyle habits, and different diet, with special reference to dental professionals, consumers of marine food and smokers, as a group of subjects that could have a higher concentration of this metal. To determine the mercury content in urine ,atomic absorption spectrometry – a tehnique of cold vapor method was used The total content of mercury in 76 analyzed urine samples was in the range of 0.12 to 12.24 ng/mL. There was a positive correlation between the number of teeth with amalgam fillings and urinary concentrations of mercury in some donors,. In contrast, the other analyzed factors that theoretically can affect the levels of mercury inurine, did not show such correlation.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 31-34.

Total phenolic content and antioxidant activity of ethanolic extracts of Aesculus hippocastanum L. Original Scientific Article

Otajagić Senada, Pinjić Dženana, Ćavar Sanja, Vidic Danijela, Maksimović Milka

Abstract: Aesculus hippocastanum L. (horse chestnut) belongs to the genus Aesculus, the most widespread genus of the Hippocastanaceae family, and it is native to the countries of the Balkan Peninsula. Different parts of the plant were used for the treatment of many diseases. Total phenolic content of ethanolic extracts of bark of twigs and fruit and fruit itself was evaluated by Folin-Ciocalteu method while antioxidant activity was tested using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method. Preliminary investigation of chemical composition was done by TLC and aesculin was detected in samples of bark of twigs. Results for content of total phenolics were expressed as gallic acid (mg GAE/mL) and aesculin (mg AE/mL) equivalents, respectively. Among the tested samples, the highest amounts of total phenolics were detected in all bark extracts, 763.53- 1048.00 mg AE/mL, while samples of pulp had the lowest content of these compounds, 43.41-66.15 mg AE/mL. All bark extracts showed higher antioxidant activity than aesculin which was used as a standard, while extract of pulp mixed with bark showed significantly lower antioxidant potential.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 35-38.

Spectrophotometric analysis of total ascorbic acid content in various fruits and vegetables Original Scientific Article

Kapur Ajla, Hasković Alisa, Čopra-Janićijević Amira, Klepo Lejla, Topčagić Anela, Tahirović Ismet, Sofić Emin

Abstract: Total ascorbic acid (ascorbic acid + dehydroascorbic acid) has been determined in twenty-one different samples of fruits and vegetables by spectrophotometric method. This method is based on the oxidation ascorbic acid to dehydroascorbic acid by bromine water in the presence of acetic acid. After coupling with 2,4-dinitrophenylhydrazine (DNPH) a red complex was produced and absorbance of that complex was spectrophotometrically measured at 521 nm. A linear concentration range for standard solutions of ascorbic acid was obtained up to 10 μg mL^-1, with a correlation coefficient of 0.9929. The contents of ascorbic acid were found between 9 and 49 mg/100 g of fresh fruits, also 3 and 90 mg/100 g of fresh vegetables. The interferences of glucose, fructose and sucrose were also investigated. The limit of detection of ascorbic acid was found to be 0.01 μg mL^-1 (3σ from 10 measurements of ascorbic acid concentration of 3 μg mL^-1), and limit of quantification of ascorbic acid was 0.017 μg mL^-1. A relative standard deviation was 2.4% (n = 10, c = 7 μg mL^-1). The content of total ascorbic acid in twenty-one different samples of fruits and vegetables was compared with results of spectrofluorimetric method and literature values.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 39-42.

Integrated knowledge of physics and chemistry: case of Physical Chemistry course Original Scientific Article

Gojak Sabina, Galijašević Semira, Hadžibegović Zalkida, Zejnilagić-Hajrić Meliha, Nuić Ines, Korać Fehim

Abstract: One of the major achievements of the learning process is acquisition of integrated knowledge. This paper presents the first results of the degree of knowledge of the second year chemistry students in subjects relevant to the objects of physical chemistry. Data was collected using questionnaires and tests given out to students of chemistry in the academic year 2010/2011. The first results obtained show a weak and insufficient integration of knowledge in general chemistry, general physics and mathematics required for further subject courses such as physical chemistry. The negative difference in the number of points on the pretest and posttest (the results are lower for 80% of questions on the posttest) was detected, although the test was repeated after the end of the winter semester and completion of Physical chemistry course. This poor performance on tests can be an indicator of a number of difficulties in the learning process, which are identified through this research in attempt to find correct solution for this problem.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 38, 43-51.

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Bulletin of the Chemists and Technologists of Bosnia and Herzegovina

Issue 41

Publication date: December 2013

Full version of Bulletin

Table of contents

Metal Levels in Surface Soils after Different Extraction Procedures Original Scientific Article

Bećiragić Selma, Huremović Jasna, Muhić-Šarac Tidža, Memić Mustafa, Selović Alisa, Žero Sabina

Abstract:Surface soil samples collected from the Kiseljak area, Bosnia and Herzegovina, were analyzed for eight different heavy metals (Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) using atomic absorption spectrometry – flame and cold vapour techniques. Three procedures of extraction of metals from soil were used: 1) extraction with ethylenediamine tetraacetic acid (EDTA), 2) extraction with HNO3 solution, and 3) extraction with aqua regia. Results for metals are reported for the first time in soils for this region. Pseudo total metal content in soil samples can be presented by the following descending series: Fe > Mn > Pb > Zn > Cu > Cr > Cd > Hg. The categories of increased pollution and highly polluted soils are almost equally presented in the Kiseljak area. Location Kiseljak-Centar by the content of Pb and Cu belong to the contaminated soil. In the case of Cd all analyzed soil samples belong to contaminated soils.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 1-5.

GC/MS Analysis of the Essential Oil of Thymus Longicaulis Presl. from Kosovo Original Scientific Article

Hatipi Ibrahimi Mjellma, Papajani Vilma, Ćavar Sanja, Matevski Vlado

Abstract: Three samples of essential oil of Thymus longicaulis Presl. were analyzed for their chemical composition. The plants were collected in their natural habitat on three different locations in Kosovo. Aerial parts of the plant were submitted to hydrodistillation using Clevenger apparatus. Gas chromatography – mass spectrometry analysis was performed for each extracted essential oil sample. Essential oil yield resulted with 0.68-1.54% on dried weight. Analyzed essential oil constituents resulted with variation in their quality and quantity. One sample was characterised as thymol/carvacrol chemotype, resulting with 15.26% of thymol and 12.65% of carvacrol as its main constituents. Two other analyzed samples had very small amounts of thymol and carvacrol and resulted with α-terpineol (14.23%), α-terpinyl acetate (11.81%), linalool (9.63%), and myrcene (6.59%) as the main constituents for the first, and α-phellandrene (19.07%), linalool (14.22%), β-caryophyllene (9.27%), and limonene (7.83%) for the second sample, respectively.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 6-10.

Determination of Total Sulphur Content in Biological Samples by Using High Performance Ion Chromatography and Elemental Analysis Original Scientific Article

Šapčanin Aida, Jančan Gordan, Pazalj Mirha, Kresić Dragan, Pehlić Ekrem, Uzunović Alija

Abstract:The aim of this work was the assessment of total sulphur (S) content in the plants with the highest S metabolic needs and different natural and artificial fertilizers by using a High Performance Ion Chromatographic (HPIC) method and Elemental analysis (EA). 7 plants and 11 diferent fertilizers were prepared by digestion and oxidation with a mixture of perchloric and nitric acid. The HPIC method was performed with a Shimadzu Ion Chromatograph equipped with conductivity detector CDD-10A. For an EA, samples of plants and fertilizers were analyzed in an elemental analyzer LECO SC-132. The total S content in analysed plants varies from 1,85 mg S/g to 0,30 mg S/g; and in fertilizers varies from 15,82 mg S/g to 0,71 mg S/g. The used HPIC method and EA are simple, sensitive, and accurate methods that can be appliedas a reliable analytical tool for the determination of total S content in the fertilizers and plant material. Results of this analysis suggest consumption of brocoli as a significant natural source of organo-sulphur compounds and could recommend soil fertilization with sheep and rabbit manure for the cultivation of the plants with a highest S metabolic needs.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 11-14.

Evaluation of Purity of some Coumarin Derivatives by Melting Point Measurments, TLC and Scanning Densitometry Original Scientific Article

Muratović Samija, Osmanović Amar, Veljović Elma, Džudžević-Čančar Hurija, Durić Kemal, Nikšić Haris, Završnik Davorka

Abstract:Impurity remains after syntheses greatly influence properties and effectiveness of synthesized compounds. Therefore it is very important to determine its presence and remove them from the synthesized product. In order to obtain crystals of high purity, synthesized bis-4-hydroxycoumarins and benzopyranocoumarinswere purified by recrystallization and column chromatography. The success of the purification of the synthesized compounds was examined by the melting point measurements, thin layer chromatography and scanning densitometry.Only one of nine tested mobile phase systems proved successful for separation of the analyzed compounds. Detection of the compounds on TLC plates was carried out under UV light at wavelength of 254 nm, as well as quantitative analysis of the present impurities. The results of scanning densitometry showed that the corresponding compounds obtained by purification had a satisfactory degree of purity (less then 2% unknown impurities). Percentage of impurities can also be calculated from data attained by spectrometric methods and elemental analysis.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 15-19.

Laser-induced Processes of Diatomic Molecules: Homonuclear vs. Heteronuclear Species Original Scientific Article

Odžak Senad, Čerkić Aner, Gazibegović-Busuladžić Azra, Hasović Elvedin, Busuladžić Mustafa, Milošević B. Dejan

Abstract: We investigate high-order above-threshold ionization (HATI) and high-order harmonic generation (HHG) of homonuclear and heteronuclear diatomic molecules using modified molecular strong-field approximation (MSFA) and Stark-shift-corrected MSFA respectively. We present our results for N₂ and CO molecules. Their initial highest occupied molecular orbitals (HOMO) are characterized by 3σ_g and 5σ symmetry respectively, as for heteronuclear species parity property gerade or ungerade is no longer relevant. N₂ and CO HATI and HHG spectra for different molecular orientation with respect to laser polarization axis, and for different values of the electron or photon energies and emission angle, clearly reflect influence of the electron-density distribution symmetry of the HOMO. Prominent difference between these spectra is the absence of the left-right symmetry in HATI spectra for paralel orientation and selection rules violation in HHG spectra for CO. Spectra for CO could be reconstruct with contributions that accounts for ionization from the C atom only.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 20-28.

Determination of Sugar Content in Flavored Waters Technical Article

Šapčanin Aida, Jančan Gordan, Jadrić Radivoj, Pehlić Ekrem, Uzunović Alija, Durić Kemal, Rimpapa Zlatan

Abstract: Flavored waters mostly consists of water, natural or artificial flavorings, and sugar or artificial sweeteners. This work aimed to assess total sugar content in 25 different flavored water samples commercially available from the Slovenian local market by using an high pressure liquid chromatography (HPLC) method with refraction index detection (RID). HPLC (Agilent 1200 Series) was performed with an isocratic elution of mobile phase 15 mM K₂HPO₄ water solution. Degassed and diluted samples were analyzed on Supelcogel K column (300 x 7.8 mm, with 9 μm particles size), at 80 °C and 0.5 mLmin^-1 flow rate. The total sugar content in flavored waters varies according to the types and brands, from 11.0 g/L to 44.1 g/L. Concentration values of sucrose, glucose and fructose were found to be in the ranges (g/L): 10.0 – 32.8; 1.3 - 21.7 and 3.0 -37.2, respectively. The results suggest caution in the use of high amount of flavored waters especially by diabetic patients.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 29-32.

Interdependencies Between Landfill Operation Procedures and Leachate Treatment Technical Article

Mueller-Czygan Günter, Avdić Nurudin

Abstract: Leachate of landfills with organic waste consist a complex composition of different ingredients. Therefore it is not enough to design a leachate treatment plant only on the base of leachate analysis from a selected period. As a consequence, an examination of the expected development of landfill body over next 20 to 30 years must be an important part of the design in order to get an optimum solution of leachate treatment.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 33-36.

Anticorrosion Performance of eco-friendly Paint Coatings Technical Article

Korać Fehim, Gutić Sanjin, Zukić Ilda, Ostojić Jelena, Herenda Safija, Gojak-Salimović Sabina

Abstract: Principal solvent and diluent used in water-soluble paints is water, although they can contain minimum quantities of potentially hazardous organic solvents. Corrosion protection performance of this type of paints is still low compared to the organic solvent-based paints. In this paper, monitoring of dry coating thickness and adhesion, as well as salt chamber and field testing were performed in order to test coating quality. Organic solvent-based paints show superior performance compared to the water soluble paint coatings.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 37-47.

Preliminary Analysis of Heavy Metal Content in the River Bosnia Upstream and Downstream from the Industrial Plants in Zenica and Pollution Assessment Short communication

Bikić Farzet

Abstract: Thispaper presents the results of an analysis of monthly average contents of ten heavy metals in the flow of the river Bosna. The amount of toxic heavy metals, Pb, As, Cd, Hg and in addition, potentially harmful metals such as Cr, Ni, Zn, Cu, Mn, Fe was determined in order to assess the influence of industry in Zenica on the quality of the river Bosna. Samples were collected during the period ofthree months: November of 2010, January and February of 2011, during the normal water level of river Bosna. The sampling sites were chosen upstream and downstream from the industrial plants in Zenica with the aim of determining the influence of industrial complexes, mainly ArcelorMittal Zenica, on the quality of the water in river Bosna. Therating ofthe level of pollution in the river Bosna is based on the comparison of concentrations of heavy metals from the results of the analysis with the highest allowable concentrations of heavy metals by individual classes of water, MRL. The results showed that the industrial waste inZenica has no significant influence on increase of heavy metals’ concentrations in river Bosna above the maximum allowable concentration for waters of I and II classes. The results showed increased mercury content in the river Bosna, not only in the downstream flow from the industrial complex in Zenica but also from the above of mentioned plants.

Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 41, 48-51.

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