Solvents prepared from natural terpenes (menthol and thymol), as H-bond acceptors, and a series of organic acids (chain lengths of 8, 10, and 14 C atoms), as H-bond donors, were characterized and tested as reaction media for liquid–liquid extraction purposes. Due to their high hydrophobicity, they seem to be promising alternatives to conventional (nonpolar and toxic) solvents, since they possess relatively less toxic, less volatile, and consequently, more environmentally friendly characteristics. Assuming that the equilibrium is established between solvent and analyte during a ligandless procedure, it can be concluded that those nonpolar solvents can efficiently extract nonpolar analytes from the aqueous environment. Previous investigations showed a wide range of applications, including their use as solvents in extractions of metal cations, small molecules, and bioactive compounds for food and pharmaceutical applications. In this work, hydrophobic solvents based on natural terpenes, which showed chemical stability and desirable physicochemical and thermal properties, were chosen as potential reaction media in the liquid–liquid extraction (LLE) procedure for Pb(II) removal from aqueous solutions. Low viscosities and high hydrophobicities of prepared solvents were confirmed as desirable properties for their application. Extraction parameters were optimized, and chosen solvents were applied. The results showed satisfactory extraction efficiencies in simple and fast procedures, followed by low solvent consumption. The best results (98%) were obtained by the thymol-based solvent, thymol–decanoic acid (Thy-DecA) 1:1, followed by L-menthol-based solvents: menthol–octanoic acid (Men-OctA) 1:1 with 97% and menthol–decanoic acid (Men-DecA) 1:1 with 94.3% efficiency.

The conductometric study of ligand structure influence on the Pb(II) complexation with crown ethers in different solvents has been investigated. In this paper, the complexation reaction of macrocyclic ligand, 18-crown-6 (18C6), dibenzo-18-crown-6 (DB18C6), and Pb(II) cation was studied in different solvents: dichloromethane (DCM) and 1,2- dichloroethane (1,2-DCE). The effects of surfactant structure (Triton X-100 and Triton X-45) on the conductivity of the Pb(II) complex with 18-crown-6 and dibenzo-18-crown-6 ether have been investigated. The conductance data showed that the stoichiometry of the complexes in most cases is 1:1(ML). It is also demonstrated that the influence of crown ethers is deeply affected by the organic solvent used. In the solvents studied, the stability of the resulting complexes showed higher stability in dichloromethane comparing with 1,2- dichloroethane. Macrocyclic ligand 18-crown-6 showed more suitable for complexation of Pb(II) ions compared to dibenzo-18-crown-6. Adding a surfactant affected the higher absolute values of the conductivity of systems, but not the change in the stoichiometric ratio between a metal ion and macrocyclic ligand.

Schiff bases are organic compounds formed by the reaction of the primary amine with carbonyl compounds (aldehydes or ketones). These are mainly bi- or tridentate ligands capable of forming very stable complexes with transitional metals. They are used as catalysts in oxygenation, hydrolysis, electro-reduction and decomposition reactions. Many Shiff bases show significant anti-tumor and antimicrobial activity, which is why they are the subject of research by many scientists in the world. In this paper Schiff's base from benzidine and 1,3-diphenyl-1,3-propanedione was synthesized. To characterize the product, FTIR spectroscopy and stereo-microscopy were used. In order to determine biological activity, antibacterial, antifungal and antioxidant activity of the product was tested. The results showed that the interaction of benzidine and 1,3-diphenylpropandione results in a Schiff base showing antibacterial, antifungal and antioxidant activity. Keywords: Schiff base, benzidine, FTIR, UV/Vis, antimicrobial activity.

Green Tea, made from Camellia sinensis plant leaves, is one of the most popular drinks in the world. For the past decades, scientists have studied this plant in terms of potential health benefits. Research has shown that green tea helps prevent stroke, malignancy and infections. In this paper, antioxidant activity and total phenol content of 4 samples of green tea from local Tuzla stores were investigated, of which two were of foreign origin. The antioxidant activity of the samples was analyzed using FRAP and DPPH methods. The obtained results show that the highest content of total phenols and the largest antioxidant capacity has a sample of foreign origin. The content of total phenols in the samples ranges from 60.01 to 79.34 mg GAE/g. The highest FRAP value is 3.34 mmol/g. The antioxidant capacity was also confirmed by the DPPH method. The IC50 value ranges from 0.014 to 0.030 mg/mL. Keywords-Phenol, FRAP, DPPH, Green Tea

Encapsulation can be defined as a process of entrapping one substance within another substance producing particles with diameters of a few nm to a few mm. The entrapped material is usually a liquid, but may be a solid or a gas. The main reason of using encapsulation is the fact that some nutrients do not remain in the food for a significant amount of time or may react with the other food components causing undesirable effects. It is possible to use micro- and nanoencapsulation techniques. The first one, microencapsulation, is a technology that can improve the retention time of the nutrient in the food and allow controlled release at specific times, during food consumption or in the intestinal gut (microencapsulation of vitamin). Nanoencapsulation has the potential to protect sensitive bioactive food ingredients from unfavourable environmental conditions, enhance solubilisation, improve taste and odour masking, and enhance bioavailability of poorly absorbable function ingredients. In this review, some relevant aspects of encapsulation methodologies, coating materials and their uses in food technology were discussed.

A Cloud point extraction (CPE) procedure was presented for preconcentration of lead(II) ions, after complexation by 18-crown-6 (18C6) and extraction with Triton X-100 at proposed experimental conditions. After separation of surfactant - rich phase, content of Pb(II) ions in remaining solution was measured by Flame Atomic Absorption Spectrometry (FAAS). The experimental conditions such as pH, temperature, concentration of Triton X-100, concentration of 18C6, incubation time, type and concentration of added electrolyte, were evaluated. Results showed that among investigated electrolytes (NaCl, Na2SO4 and Na2CO3) the amount of 0.9 mol/L Na2CO3 lowers cloud point temperature of Triton X-100 to 22?C (room temperature during the experiment), thus simplifying the extraction procedure. After an incubation time of 5 minutes and using the concentration of 1.2?10-3 mol/L Triton X-100 and 1.5?10-4 mol/L 18C6 (1:1 stoichiometric ratio for 18C6:Pb), 60% of lead (II) ions were efficiently removed from investigated solution.