Faculty of Technology and Metallurgy
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Item type:Publication, TOWARDS SUSTAINABLE EXTRACTION OF OIL FROM APRICOT KERNELS(2026-02-12); Deep eutectic solvents (DES) are gaining attention as green alternatives to conventional volatile organic solvents for the extraction of natural products. Their ease of preparation from inexpensive, biodegradable components, along with low toxicity and tunable physicochemical properties, makes them promising candidates for designing eco-efficient extraction processes. In this work, four DES systems based on choline chloride (ChCl) as hydrogen bond acceptor and different hydrogen bond donors glycerol, lactic acid, acetic acid, and glucose were synthesized and evaluated as co-solvents with n-hexane for the ultrasonic-assisted extraction of oil from apricot kernels. The DESs were characterized in terms of pH, density (δ), viscosity (μ), and electrical conductivity (σ) to better understand how their physical properties influence extraction performance. Oil extraction experiments demonstrated that the DES composition and its physical properties have a marked impact on extraction efficiency. Under optimized ultrasonic conditions, the use of ChCl:AA (1:2) as a co-solvent with n-hexane yielded the highest oil recovery of 26.62%, surpassing pure n-hexane, which afforded only 24.10% under the same conditions. In contrast, ChCl:GLY (1:2), ChCl:LA (1:2), and ChCl:GLU (2:1) resulted in lower oil yields of 18.95%, 22.23%, and 13.26%, respectively. The superior performance of ChCl:AA is attributed to its combination of relatively low viscosity, and high conductivity, which collectively promote enhanced mass transfer, more efficient cell disruption, and improved solubilization of lipophilic components when assisted by ultrasonic cavitation. Overall, this study highlights the importance of tailoring the physicochemical properties of DES to maximize performance and demonstrates the potential of DES n-hexane systems as green, efficient, and scalable alternatives to conventional solvent based processes for the valorization of apricot kernel oil and other plant derived lipids. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimization of Oil Extraction Process from White Mustard Seeds Using Response Surface Methodology(National and University Library of the Republic of Srpska, 2024-02-21); ; In this study, response surface methodology (RSM) was used for the determination of the effect of two process parameters (extraction temperature and extraction time) and their interaction on the yield of the total extract from white mustard seeds (Sinapis alba l.), as well as the creation of a mathematical model, 3D response surface, and the establishment of an optimal extraction region. Ethanol 96% as a green solvent was employed to separate biological compounds from white mustard (Sinapis alba l.) seeds by applying ultrasound-assisted extraction (UAE). UAE was performed at the temperature of 25, 30, and 35℃ for a duration of 30, 60, and 90 min. UAE as a modern extraction technique showed great performance, while the ethanol solvent provided a high yield of compounds. The utilized RSM design adequately fit the experimental data with a high coefficient of determination (R2= 0.9365) and low mean absolute error (MAE= 1.12242). Estimated effects for the yield of the total extract showed that the extraction time, the temperature, and the interaction between time and temperature influenced positively, while the time-squared and the temperature-squared influenced negativity on the yield of the total extract. Analysis of variance showed that 2 effects have P-values less than 0.05. The optimal yield of the total extracted oil was 15.19% at the temperature of 35℃ for a duration of 70.3 min. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electrochemical sensors based on polymer-modified screen-printed graphene electrodes for the detection of pharmaceuticals in aquatic environments(SAGE Publications, 2025-10-06); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, REDUCING THE BAND-GAP ENERGY OF TiO2 AS A CRUCIAL OBJECTIVE IN GREEN PHOTOCATALYSIS(Ss Cyril and Methodius University in Skopje, Faculty of Technology and Metallurgy, 2025-06-12)Perica Paunović, Anita Grozdanov, Petre Makreski, Martin Stojčevski, Kiril Stoimčev, Gorazd ČepiševskiGreen photocatalysis focuses on developing processes to address various environmental challenges, such as the treatment of contaminated water and air, the generation of renewable energy, biomass management, carbon monoxide oxidation, and organic synthesis. TiO2 nanoparticles are relatively inexpensive, non-toxic, and chemically stable. They are available in diverse structural forms and exhibit unique semiconductive properties, making them the most widely utilized photocatalysts in this domain. TiO2 has a wide array of applications in green photocatalysis, including i) photocatalytic remediation and ii) the development of alternative, sustainable energy sources. A significant challenge in modern green photocatalysis is the reduction of the band gap energy (Eg), which is essential for determining the suitability of materials for photocatalytic activity. Decreasing Eg enables TiO2 to effectively harness visible light rather than being limited to ultraviolet light. This study investigates the structural changes and subsequent reduction in Eg resulting from two types of TiO2 modification: i) ionizing irradiation and ii) the incorporation of carbon nanotubes. We synthesized TiO2 nanoparticles using our proprietary sol-gel method, followed by thermal treatment at 400 °C. Structural changes were analyzed using X-ray powder diffraction (XRPD) and Raman spectroscopy, while the band gap energy of the samples was assessed through UV-Vis spectroscopy. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Polymer-modified screen-printed electrode-based electrochemical sensors for doxorubicin detection(The Association of South-East European Electrochemists (ASEEE), 2025-02-27)Iva Dimitrievska, Perica Paunovikj, Anita GrozdanovIn the last decade, intensive research has been performed in the field of analytical electrochemistry, seeking designs of electrochemical sensors capable of providing better analytical characteristics in terms of sensitivity, selectivity, reliability, ease of fabrication and use, and low cost, especially for pharmaceutical drug monitoring. Our research has primarily focused on developing screen-printed electrode-based sensors and their application as electrochemical platforms for drug determination and monitoring, specifically emphasizing their suitability for surface modification. A commercial screen-printed graphene electrode was used as the electrochemical sensing component, which was subsequently modified with polymers, such as polyvinylidene fluoride and chitosan. All studied electrodes were tested using a doxorubicin hydrochloride (DOX) solution with a concentration of 0.002 mol L-1 dissolved in 0.1 mol L-1 phosphate-buffered saline at pH 6.7. Cyclic voltammetry was used as an electrochemical characterization technique to gather data on all tested electrodes' electrochemical activity. The morphological characterization of the electrodes was done using scanning electron microscopy. The changes in the electrolyte during the electrochemical measurements were followed through ultraviolet-visible spectroscopy. The modified electrodes demonstrated a favorable electrochemical response to DOX and exhibited higher electrical conductivity than the commercial one. The characterization results indicated that the Ch-modified electrode exhibited excellent electrochemical conductivity and demonstrated strong electrochemical performance. The evaluations of this electrode comprised the definition of the lowest limit of detection and limit of quantification among the tested electrodes, with values of 9.822 and 32.741 µmol L-1, respectively, within a linear concentration range from 1.5 to 7.4 µmol L-1. Additionally, the electrodes showed excellent repeatability, stability, and reproducibility, confirming their suitability for sensitive DOX detection. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of irradiation treatment on sensing performances of screen-printed electrodes aimed for doxorubicin monitoring(Association of South-East European Electrochemists (ASEEE), 2025-05-05)Perica Paunovikj, Iva Dimitrievska, Marija Katerina Paunovikj, Marija Mitevska, Anita GrozdanovThe subject of study is the development of nanosensors based on carbon nanotubes (CNTs) and polyaniline (PANI) aimed at effective detection and monitoring of doxorubicin - a chemotherapy drug used in the treatment of different types of cancer. The main goal is the design of nanosensors that provide precise and reliable detection and monitoring of doxorubicin, providing an effective approach to monitor drug levels during treatment. The research was carried out on the screen-printed electrodes (SPE) with a working electrode of commercial CNTs and PANI and their modification by irradiation with electron irradiation (50 kGy). The structural changes resulting from the e-beam irradiation were observed by scanning electron microscopy, Raman and FTIR spectroscopy, and thermogravimetric analysis. An electrochemical study employing cyclic voltammetry was done to characterize and test the performance of the nanosensors. Modification with electron irradiation was shown as an effective approach to improve the sensing characteristics of the studied SPE, resulting in a lower limit of detection for the modification. The irradiated SPEs exhibit a limit of detection of 12.674 µmol L⁻¹ for the modified multi-walled CNT (MWCNT) electrode and 12.712 µmol L⁻¹ for the modified PANI electrode, compared to 12.773 µmol L⁻¹ for the MWCNT and 12.712 µmol L⁻¹ for the PANI commercial electrodes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Characterization of Al-Containing Industrial Residues in the ESEE Region Supporting Circular Economy and the EU Green Deal(MDPI AG, 2024-12-20) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Voltammetric Detection of Diclofenac with Screen-printed Electrodes Based on Graphene and PVDF-Modified Graphene(The Croatian Society of Chemical Engineers – CSCE, 2024-07-15) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of baking time and formulation of part-baked wheat sourdough bread on the physical characteristics, sensory quality, glycaemic index and appetite sensations(Frontiers Media SA, 2024-06) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis and Characterisation of Nano Zero-Valent Iron for the Reduction and Immobilisation of Cr(VI) in Water Resources(The Croatian Society of Chemical Engineers – CSCE, 2025-03-15)Martin Stojchevski, Stefan Kuvendziev, Zoran Bozinovski, Petre Makreski, Perica Paunović, Mirko Marinkovski, Kiril LisichkovNano zero-valent iron (nZVI) was synthesised through the chemical reduction of Fe(III) ions using iron(III) chloride and sodium borohydride solutions under atmospheric conditions. Structural and chemical characterisation of nZVI was performed using scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), energy dispersive X-ray fluorescence spectrometry (EDXRF), thermogravimetric/differential thermal analysis (TGA/DTA), specific surface area analysis (SSA), and ultraviolet-visible spectroscopy (UV/Vis). The synthesised iron exhibited a zero oxidation state and a nearly one-dimensional morphology. The zero-valent iron nanoparticles with a body-centred cubic crystal structure remained chemically stable for several months. The mean diameter of individual nanoparticles was less than 60 nm, with an SSA of 23.79 m2 g–1. The synthesised nZVI was applied for the catalytic reduction of Cr(VI) in an aqueous solution. The effects of contact time and initial nZVI concentration on the efficiency of Cr(VI) removal from aqueous solution were investigated. The removal efficiency reached 44.2, 74.6, and 94.5 % after 300 min at initial nZVI concentrations of 20, 40, and 60 mg l–1, respectively. This study suggests that the obtained nZVI is an environmentally friendly and effective reducing agent for treating wastewater and groundwater contaminated with hexavalent chromium.