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Bulletin of the Chemists and Technologists of Bosnia and Herzegovina
Issue 44
Publication date: June 2015 |
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Table of contents
Antioxidant activity and total phenol content of white wine Žilavka Original Scientific Article
Marković Marijana, Martinović Bevanda Anita, Talić Stanislava
Abstract: It is already well known that wine consist of different compounds with strong antioxidant activity. Among them, most common ones are different phenol compounds generally separated in two major groups; flavonoids and nonflavonoids. In this paper we determined total phenol concentration and antioxidant activity of Herzegovinian white wines. Eighteen commercially available white wines made from autochthonous grape varietiesŽilavka (vintage 2011) were analyzed. Total phenol content was determined spectrophotometrically according to the Folin-Ciocalteu method using gallic acid as a standard. Two distinct methods were used to assess the antioxidant activity of tested wines: spectrophotometric monitoring of 2,2-diphenyl-1-picrylhydrazyl(DPPH·)free radical scavenging activity and Briggs-Rauscher (BR) oscillating reaction method. Total phenol concentration in wine samples varied from 249.3 ±SDmgL-1 to 801. ±SDmgL-1 expressed as mg of gallic acid equivalent per liter of wine, determined from a standard calibration curve. Similar antioxidant activity was obtained by both performed methods. The antioxidant capacity obtained by DPPH·method ranged from 28.8%±SD to 70.2%±SD. In some cases, the results obtained using both, DPPH·and BR methods, confirmed the fact that wines with higher total phenol content have stronger antioxidant activity.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 1-4.
Phenolic content and antioxidant activity of mushroom extracts from Bosnian market Original Scientific Article
Alispahić Amra, Šapčanin Aida, Salihović Mirsada, Ramić Emina, Dedić Amila, Pazalja Mirha
Abstract: Mushrooms are well balanced food that provides definite nutrition and health benefits for humans. Mushrooms are known to produce different kinds of bioactive compounds, generally linked with mycelial cell wall, that help in enhancing the capacityof immune system to fight against carcinogens. To consider the importance of polyphenolic compounds and its presence in many varieties of mushrooms, the total antioxidant activity of dry boletus mushroom, white and brown champignon, oyster mushroom and shiitake from bosnian markets was determined. Total phenolic content was estimated as Galic acid equivalents /g spectrophotometrically according to the Folin-Ciocalteus method. Total anthocyanine content was analysed by pH differential spectrophotometric method at 525 and 700 nm. The radical scavenging activity (
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 5-8.
Investigating the optimum fineness of the coal grain in the Brown Coal Mine Kakanj in order to fully exploit its calorific value Original Scientific Article
Avdić Nurudin, Šehagić Indira
Abstract: In an array of mechanical operations undertaken during the processing of raw coal at the reloading system of the “Vrtlište” open-cut mining in the brown coal mine Kakanj, the tendency is to separate the combustible from the non-combustible parts of coal all with the aim of obtaining a product with higher calorific value and fewer ash components. Depending on the physical and chemical composition of the raw material and the purpose of the obtained product, our objective was to determine the optimal size of the coal grain in the “Brown Coal Mine Kakanj” whereby the most agreeable aspect in terms of the energy value was to separate the valuable fractions from the tailings. It was established that the top-quality granulation in the raw material being delivered to the client in terms of its energy characteristics is -40+35 mm with a calorific value of 16918 kJ/kg followed by -35+20 and -20 +10 with a calorific value of 13035 kJ/kg and 13819 kJ/kg respectively. They generate the smallest amounts of ash after combustion while the free, hygro and total moisture have the lowest values in these samples.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 9-16.
The effects of problem-based learning on students' achievements in primary school chemistry Original Scientific Article
Zejnilagić-Hajrić Meliha, Šabeta Alma, Nuić Ines
Abstract: Specific applications of cognitive and constructivist theories in problem-based learning (PBL) include connecting prior knowledge and skills with new information. This prominent instructional method is widely accepted in higher education around the world, but it also shows good results when applied in primary education of various disciplines. This paper presents effects of PBL application in 8th gradeprimary school chemistry when learning about chemical compounds, using questionnaires and tests of knowledge in pretest-posttest study with control (CG) and experimental (EG) groups. Students in CG were taught in usual way with teacher-centered approach, while in EG the PBL materials designed for the purpose of this study were applied. Results showed (1) significant improvement of students’ achievements in EG, (2) these students are not used to this teaching method so they encountered certain difficulties, (3) overall interest and engagement in chemistry lessons has increased.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 17-22.
Dependance of viscoelastic properties of two emulsion formulations on preparation process Original Scientific Article
Elezović Alisa, Kostić Slobodanka, Hadžiabdić Jasmina, Rahić Ognjenka, Vranić Edina, Vehabović Midhat
Abstract: Rheological properties are crucial for cosmetic formulations, determining product’s properties during production and application. O/W emulsions (pH 6.86–7.10) were prepared with decyl-oleate as internal phase. A-formulations contained K-stearate, while N-formulations contained polyglyceryl-stearate and -behenate as principal emulsifiers. The formulations were prepared by adding the water to the oil phase (NA and AA) or vice versa (NB and AB). Oscillatory measurements were performed on Haake RheoStress using double gap cylinder. In amplitude sweep at low stresses all samples behaved as viscoelastic solids. With increasing stress, phase angles increased to >80o. Crossover of storage and loss moduli for AA happened at nine times higher stress compared to the other formulations, forming lamellar crystalline gel network. Linear viscoelastic region showed that AA was much more stable. Frequency sweep showed NA and AB to be liquid-like. In NB and AA decrease in complex viscosity indicates better spreadability. Stability of phase angles and storage and loss moduli indicate more elastic behavior. New nonionic emulsifier was more independent of processing, unlike anionic emulsifier. However, AA formulation gives much better feel properties, needed in cosmetic formulations.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 23-28.
Spectrophotometric determination of total iron content in black tea Original Scientific Article
Mandal Šaćira, Banjanin Božo, Kujović Ismir, Malenica Maja
Abstract: The aim of this work was the assessment of total iron (Fe) content in some black tea brands using mineral digestion and spectrophotometric method. Four samples of black tea from different manufactures in three parallels were prepared by digestion and oxidation with a mixture of sulphuric and nitric acid. The total Fe content in analyzed black tea varies from 21.3mgFe/kg to 37.6mg Fe/kg. The used spectrophotometric method is simple and sensitive method that can be applied for the determination of total Fe content in plantmaterial.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 29-32.
Influence of chloride ions on various corrosion resistance of Zinc coating Original Scientific Article
Ličina Sara, Ostojić Jelena, Gutić Sanjin, Cacan Merzuk
Abstract: Corrosion is one of the major causes for global crisis concerning the loss of materials resources and energy. It is also the cause of significant economical loss in many countries. Certain measures can be taken to minimize this problem, which is the first and foremost goal of this research work. The objectives of this study are to investigate respective aspects of chloride ions influence on various galvanic properties of zinc coating. Those included: corrosion resistance properties, the effects different concentrations of chloride solutions thereon, also the properties of galvanically deposited zinc in a variety of coating thicknesses with respect to corrosion resistance of galvanically deposited zinc in chloride solutions and the influence of chloride ions on the zinc coating given by different technologies, as warm and galvanic processes, analysis of their properties on corrosion resistance. All tests were performed with potentiostat/galvanostat Model 263A, guided by potentiodynamic polarization and linear polarization method. Based on the results presented in this research work, it is concluded that despite the costs the corrosion protection is the most effective way to prevent material loss.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 33-38.
Validation of method for the determination of mercury in the auxiliary substances azorubine 21%and azorubine 85% using cold-vapor atomic absorption spectrometry Original Scientific Article
Petinac Sanel, Mulaosmanović Edhem, Mahmutović Omer, Omerović Samira, Džudžević Čančar Hurija
Abstract: Heavy metals, such as mercury (Hg), sometimes can be found in auxiliary substances intended for pharmaceuticals use. Although the concentration of those elements is very low, their control isvery important because of its toxicity. Permissible concentration of mercury (Hg) in Azorubine 21% and Azorubine 85% is prescribed by the Directive of the European Commission concerning the specific purity criteria on food coloring. The focus of this paper is on validating reliable methods of Hg determination in auxiliary substances mentioned above, by Cold-vapor Atomic Absorption Spectrometry after microwave acid digestion of solid samples. To obtain possibly present Hg in Azorubine by conversion to Hg2+ ions, samples were treated with a mixture of 1 mL MQ water + 1 mL 65% HNO3 + 1 mL 70% HClO4 + 5 mL 96% H2SO4 and heated by microwave for 30 min. on 1000 W in sealed TFMTM – PTFEtubes. The resulting solutions are diluted and analyzed for Hg using cold vapor atomic absorption spectrometry with sodium borohydride as a reducing agent. The method was successfully validated and can be applied for the determination of Hg in solid samples of Azorubine 21% and Azorubine 85%, with value of recovery factor of 95% to 104% and 96% to 105%, respectively.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 39-42.
Antioxidant and prooxidantactivities of phenolic compounds of the extracts of Echinacea purpurea(L.) Original Scientific Article
Jukić Huska, Habeš Suad, Aldžić Asmir, Durgo Ksenija, Kosalec Ivan
Abstract: Background and objectives: In recentyears, there is a growing intereston natural and safer antioxidants.So far, little is known about the cytotoxic and (anti) oxidative potential of echinacea (Echinacea purpurea) extracts. Methods:In order to evaluate the antioxidant activity of extracts, total phenolics content and the scavenging capacity on DPPH˙ radicals was determined. The ability of extracts to scavenge superoxide and hydroxyl radicals was tested using electron paramagnetic resonance (EPR) techniques. Also, the extracts were screened for cytotoxicity and antioxidative/prooxidative potential by neutral red and DCFDA assay respectively, usinghuman colon cancercell lineSW480. The cells wereexposed to various concentrationsof extracts (range:0,008; 0,08; 0,8; 1; 10 i 20 mg/mL) and different treatmenttimes (2, 3, 4 and 24h). Results: Thecontent of total phenolic compounds of extracts of E. purpureawas 10.57 % GAE. The scavenging activity of radicals was found to exhibit 50% of the inhibition value (IC50 value) at the concentration of 15.67 μg/ml for the investigated echinacea extract. Also, the calculated value of 210 mg/ml for hydroxyl and 76.7 mg/ml for superoxide anion radical indicates that the Echinacea extract is rich in antioxidant compounds that neutralize investigated radical species.In in vitro experiments, echinacea extract showed prooxidant effect at lower concentrations and shorter incubation period when SW480 cell line was used as test system. The highest concentration was also the most toxic which is particularly evident after 24 hours of treatment.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 43-52.
Mycelial growth rate and yield of oyster mushroom – Pleurotus ostreatus fruitful part (Jacquin: Fr.) Kumm at different temperatures Original Scientific Article
Turković Samir
Abstract: In this paper are presented possibilities for production of oyster mushroom, its mycelium and compost, as well as how different temperatures affect the mycelial growth and yield of these mushrooms. Mycelium was cultivated on the PDA media, which was later transferred onto the sterilized wheat grains and at the end in the compost made from beech sawdust and hay. The ratioof sawdustandhaywas1:1.Compostcan be preparedfrom50%wheat straw +50% soybean straw, 50%wheat straw +50% corn stems, 50%wheat straw and 50% sunflower stems. The mycelium which was growing at an average temperature of 20 °Cafter 15 days was ready for the next grafting, while the mycelium, which was kept at 4 °C for the same period, had very slow growth rate. Mycelium was then inoculated onto sterile grain of wheat, which at a temperature of 20 °C grown very quickly. Two seedlings on compost were made, summer and autumn. The average air temperature during the summer seeding was 19.96 °C and in autumn 13.85 °C. It was found that the yield from the summer seeding was 17.76%, while the yield of autumn seeding was 7.2% relative to the weight of the wet substrate. Low temperatures, around 4oC have inhibitory influence on the mycelium growth and in such conditions mycelium can be stored up to one year. The average temperature of 19.96 °C is ideal for the growth of both mycelium and mushrooms, as well as the expected yield.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 53-58.
Changes in lecithin concentrations in human blood with aging Original Scientific Article
Ajanović Atifa, Sofić Emin, Tahirović Ismet, ŠapčaninAida, UzunovićAlija, Krehić Jasmina, Gojak Refet, Dizdar Muamer
Abstract: Lecithin is a phospholipid and a major structural component of the cell membrane. The aim of this study was to determine the lecithin concentrations (LC) in the human blood depending on age. Lecithin was measured in the human plasma (807) and wholeblood (787)of men and women aged 0.6 to 90years, by using a commercially available enzymatic kit, which is based on the spectrophotometric determination. All samples were divided into four aging groups: children (0-12 years), adolescents (13-20 y.), work-active group (21-60 y.), and older group (>60 y.). The plasma LC of all males (397) were very similar to those of females (410) (mean 3.01±0.91 mmol/l, and 2.99±1.02 mmol/l, respectively). However, within both gender, the plasma LC increased with aging. The LC in whole blood increased with aging in males, but in the work-active group, and in older group of women, the whole blood lecithin decreased without statisticalsignificance. Also, the LC in whole blood of older women were statistically lower than the LC in older men (p***<0.001, Mann-Whitneytest), while the LC in whole blood of other groups of both gender were mainly uniform. The lecithin ratio in plasma and whole blood was »1:2 in all aging groups.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 59-64.
Students with disabilities and chemistry education: Possibilities and difficulties Original Scientific Article
Zejnilagić-Hajrić Meliha, Delić Ena, Nuić Ines
Abstract: Education of students with disabilities in B&H is regulated by law for primary and secondary education by responsible institutions (ministries). It can be implemented in regular schools with or without adopted curriculum, and in special centers for their education. This paper presents results of study conducted in two centers: for secondary school students with visual (CSSDO) and hearing (CSGR) impairments. The aim of the study was to explore their knowledge and interest in studying chemistry at university level. Results showed: (1) there is no significant difference in students’ achievements on knowledge test in general chemistry (GC) in CSSDO and CSGR, (2) considering their achievements in GC, they have a chance to enroll to university majoring in chemistry based on earlier entrance exams, (3) majority of students would like to enroll to university after secondary school, (4) but only one student would consider studying chemistry. These results show significant obstacles for students with disabilities to enroll to university, especially when studying science, but also the lack of proper education for teaching staff both at university and in secondary school when it comes to education of students with disabilities.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 65-70.
Pigments and genome size variation in Symphyandra hofmannii population Original Scientific Article
Parić Adisa, Karalija Erna, Pustahija, Fatima, Šiljak-Yakovlev, Sonja, Muratović, Edina
Abstract: Thephotosynthetic pigments, total anthocyanin content and genome size in six natural populations of endemic species Symphyandra hofmanniiPant. (Hoffman's ring bellflower) from Bosnia and Herzegovina were investigated in the present study. The intrapopulation and interpopulation analysis of Symphyandra hofmannii growing under different environmental conditions were achieved. The interpopulation analysis of individuals developed under different environmental conditions had shown statistically significant differences for all investigated parameters (chlorophyll a and b, total chlorophyll, chlorophyll a/b ratio, carotenoids, anthocyanins and DNA amount). Statistically significant differences between individuals from the same population and different habitats, in chlorophyll b, a/b ratio and anthocyanins content, were also apparent. Interpopulation pigments’ variation could not be related to light as only differential ecological parameter. This variation was depended on combined environmental conditions, such as geological substrate, altitude or anthropogenic factors. The genome size was significantly higher only for one serpentine population (Papratnica).
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 71-78.
Investigation of potentially contaminated areas in the Federation of Bosnia and Herzegovina with depleted uranium Technical paper
Nuhanović Mirza, Vidic Alfred, Ilić Zorana, Kaldžija Naida, Pušina Naida
Abstract: During the war in Bosnia, depleted uranium was used on several - locations in Bosnia and Herzegovina, including the area of Hadzici. Estimated amount of used ammunition is close to three tons. Only a fraction of depleted uranium penetrator, detected in the surface ground layer was removed.A certain number of ground, moss and subterranean water samples have been collected in december 2013, for the purpose of evaluation of two decade long contamination from depleted uranium ammo usage. The colected samples were subjected to radiochemical separation and alpha-spectrometric analysis.The results of the examination showed that the uranium was present in the amount of 0.6 to 1.8 µg/kg in the ground samples, 0.2 to 7.0 µg/kg in the moss samples and 0.36 to 1.04 µg/L in the subterranean water. The activity ratio of 234U/238U in three moss samples, as well as one ground sample, showed the presence of depleted uranium. Analyzed water samples indicated a natural relation of uranium isotopes.Tests shows that the presence of depleted uranium deserves detailed examination of radioactivity, radioecology assessment and evaluation of population exposure.
Bulletin of the Chemists and Technologists of Bosnia and Herzegovina 44, 79-82.
