Schiff bases are organic compounds formed by the reaction of the primary aminewith carbonyl compounds (aldehydes or ketones). These are mainly bi- or tridentateligands capable of forming very stable complexes with transitional metals. They areused as catalysts in oxygenation, hydrolysis, electro-reduction and decompositionreactions. Many Shiff bases show significant anti-tumor, antimicrobial and antifungalactivity, which are the subject of research by many scientists in the world.In this paper Schiff base from benzidine and 1,3-diphenyl-1,3-propanedione wassynthesized. To characterize the product, FTIR spectroscopy and stereo-microscopywere used. In order to determine biological activity, antibacterial, antifungal andantioxidant activity of the product was tested.The results showed that the interaction of benzidine and 1,3-diphenylpropanedioneresults in a Schiff base showing antibacterial, antifungal and antioxidant 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 IC 50 value ranges from 0.014 to 0.030 mg/mL.

Cloud point extraction (CPE) is an attractive technique that reduces solvent con- sumption and exposure, disposal costs, and process time. This method has an im- portant practical application and is used to separate and concentrate the analyte as a step before its determination, and after the formation of a poorly water-soluble complex. Use of nonionic surfactants as ”green solvents” which represent an effec- tive alternative to toxic organic solvents (in classical extraction), along with other advantages, such as low cost and low flammability, makes this method attractive and worth further research and optimization. This paper presents a detailed de- scription of the principles, procedure, advantages, disadvantages and application of CPE.

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, Na 2 SO 4 and Na 2 CO 3) the amount of 0.9 mol/L Na 2 CO 3 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.

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