Химия

At present, the most common industrial method for producing high-quality gasoline, characterized by high octane numbers and moderate aromatic hydrocarbon content, particularly benzene, is catalytic reforming. In the current trend of oil refi ning industry development, a promising method for improving straight-run motor fuels is co-processing, where the combination of the most optimal parameters allows for the production of high-octane gasolines with the best performance and environmental characteristics.

Nonwovens produced through electrospinning technique have been successfully used in various fi elds due to their unique properties. It is essential to investigate the impact of the parameters in the manufacturing process on the resulting properties of these materials. This research focuses on nonwovens made from fl uoroplast P(VDF-TFE) using a horizontal spraying system with a vertically positioned collector. The parameters studied include the interelectrode distance, the electric fi eld strength, and the viscosity of the molding solution.

Indicator papers based on immobilized copper (II) sulfate have been obtained for the determination of the β-lactam antibiotic ceftriaxone. The interaction of immobilized copper (II) sulfate with ceftriaxone has been assessed using diff use refl ectance spectroscopy. Methods have been developed for visual colorimetric and colorimetric determination of the antibiotic using a smartphone camera, Adobe Photoshop CS5® software, and a regression model built using the Python programming language. Color test scales for rapid assessment of ceftriaxone content have been obtained.

Hydrogenated derivatives of acridine exhibit various types of biological activity – their antibacterial, antitumor, antiviral, psychoactive properties are known. Using the example of heteroanalogs of tacrine, a known cholinesterase inhibitor, it is shown that the replacement of the benzene ring in polycyclic systems with a fi ve-membered heterocycle leads to a decrease in the toxicity of the drug, but does not change the basic physiological activity. Thus, the synthesis of heteroanalogs of known benzannelated systems is an urgent task.

Tetrahydroquinolines are important structural fragments of many biologically active compounds exhibiting antifungal, antitumor, antiviral and neurotropic properties. This paper presents methods for the synthesis of N-substituted tetrahydroquinoline-6-carbaldehydes and a study of the possibility of their olefi nation using the Wittig and Horner – Wadsworth – Emmons methods. As a result of the interaction of N-alkyl- and N-acylhydroquinolines with the Vilsmeier – Haack complex, N-substituted tetrahydroquinoline-6-carbaldehydes have been obtained in yields of 77–85%.

The interaction of sands as artifi cial geochemical barriers with nickel chloride solutions simulating technological effl uents is investigated. The eff ect of pre-acid treatment of sands on their ability to absorb nickel (II) ions is considered experimentally. In experiments, sands with diff erent quartz contents have been studied, in which the only impurity element was aluminum oxide in an amount from 1 to 10% (wt.).

Modifi ed screen-printed potentiometric sensors sensitive to cephalosporin antibiotics – cefuroxime (Cefur), cefotaxime (Ceftx), cefazolin (Cef) have been developed. Tetradecylammonium associates with complex compounds silver (I) – cefuroxime (cefotaxime) have been used as electroactive components. The role of magnetic nanoparticles Fe3O4 and cetylpyridinium chloride in improving the electroanalytical properties of sensors in solutions of the studied antibiotics is shown. Optimal ratios of modifi ers in carbon-containing inks (Fe3O4 : CPCh = 1 : 2.5) have been found.