Ceria particles were synthesized in the aqueous ammonia solution in presence of hydrogen peroxide or sodium citrate. The obtained sols were exposed at room temperature for 6 hours, thеn treated with ultrasound or heated under pressure (~80 kPa). After sonication the absorption intensity of the particles increased by 3.4–3.7 times, as compared to the particles aged at room temperature or heated under pressure. Addition of H₂O₂ or Na₃C₆H₅O₇ in the synthesis medium leads to the reduction of hydrodynamic diameter of particles (116–216 nm) and polydispersity index of the sol (0,18–0,27). The resulting ceria particles are able to oxidize 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and decompose H₂O₂. The highest «oxidase» activity showed the particles treated with ultrasound. Their «catalase» activity decreases with the increase of H₂O₂ concentration.

 

 

Acid-base properties of zeolite tuffs of Cheboksary, Holin and Tedzamy deposits were studied by potentiometric titration of their decationized forms with HСl solution at concentration of background electrolyte 1 M and 0.1 M КСl. The acidity parameters of individual types of the clinoptilolite ion-exchange centers of have been calculated from the titration curves of the zeolites using the method of computer modelling of potentiometric titration data suggested earlier. The full exchange capacities were determined by К⁺ ion using static and dynamic methods. Potentiometric titration was carried out by the titration of the zeolites using one sample method. The clinoptilolites contain at least three types of the sorption centers. They differ in the acid strength expressed by the pK parameter and its dependence of the degree of neutralization ∆pk. The amount of strong acidic groups (pK₁= 0.2) is 0.13–0.26 m-eq/g. The number of weak acid groups in the samples of clinoptilolites is different (pK₂ > 3 and pK₃ > 7).

 

 

 

The results of investigation of corrosion inhibition of zinc-plated coatings in neutral chloride-containing corrosive medium by aqueous sodium vanadate solution are described. Investigations of corrosion inhibition of zinc-plated coatings on steel were performed by gravimetric and electrochemical method. The corrosive medium was neutral 3% sodium chloride solution, with a sodium vanadate concentration varied from 0.00005 M to 0.0003 M. Mass indices of corrosion, current density and corrosion potential of galvanized steel were determined depending on inhibitor concentration. Electrochemical studies show that the introduction of sodium vanadate in amounts of 0.00005–0.0003 M into the corrosive medium (3% sodium chloride solution) slows down the process of zinc corrosion. The corrosion process slows down by 3.3 times at an inhibitor concentration of 0.00005 M and by 20 times at an inhibitor concentration of 0.0002 M, respectively. An increase in the concentration of sodium vanadate to more than 0.0002 M is inappropriate, since an increase in the corrosion current occurs. The optimal corrosion inhibitor concentration for zinc-plated steel in 3% NaCl solution for Na₃VO₄ lies in the range of 0.0001–0.0002 М. The protection effect of the inhibitor found by gravimetric and electrochemical methods equals to 40–76% and 93–95%, respectively.

 

 

The compositions of surfactants based on carboxylic acids and aliphatic amines with a different number of amino groups in the chain and the length of the hydrocarbon radical were obtained using the methodology of “green chemistry” by realization of the principle of multicomponent reactions. The information about the basic functional groups and structure of the objects of study: epoxidated rapeseed oil, which is one of the sources of organic acids in the compositions, and anionically-oriented synthesized zwitterionic surfactants, was obtained using IR-spectroscopy. Based on the results of surface tension at the solution - air interface measuring by du Noüy ring method, the isotherms of surfactant aqueous solutions in an alkaline medium were plotted and the colloid-chemical properties, such as surface tension of the surfactant aqueous solution under the critical micelle concentration, the Gibbs free energy of adsorption, the surface activity and the hydrophilic-lipophilic balance, were defined. All investigated surfactant compositions were shown to reduce effectively the surface tension (up to 25.2 mN/m), while the critical micelle concentration and the hydrophilic-lipophilic balance decrease with the increase of hydrophobicity degree in the amine homologous series due to the increase of the length of the hydrocarbon radical. The absolute value of the standard free energy of adsorption increases with the increase of hydrophobicity degree. The high values of hydrophilic-lipophilic balance for the investigated surfactants (16 ÷ 22) make it possible to use them as effective emulsifiers for preparation of type I (oil / water) emulsions and foaming agents. The foaming capacity of the surfactant based on oleic acid and pentaethylenehexamine was estimated as well.

The possibility of stripping-voltammetric determination of Zn, Cd, Pb, Cu, Hg trace amounts in vegetable oils without the use of mineralization procedure has been demonstrated. It has been established that high sensitivity of the method (<0.001 mg/dm>3) can be achieved for Zn, Cd, Pb, Cu by cathodic accumulation on the surface of the amalgamated silver indicator electrode, and by the accumulation of mercury on the electrode containing 58 % Au, 34 % Cu, 8% Ag. The amount of the deposited metal has been determined by the magnitude of the anodic current in an aqueous-acetone electrolyte containing formic (Zn, Cd, Pb, Cu) or sulfuric (Hg) acid additives. Analysis of twelve refined and unrefined vegetable oil samples (sunflower, olive, linseed, rapeseed, and corn) showed the presence of trace impurities of zinc (0.6–9.6 mg/dm3), lead (0.02–0.09 mg/dm3), and copper (0.02–0.17 mg/dm3). Additional traces of mercury (0.002–0.009 mg/dm3) were detected in eight oil samples and cadmium traces (0.02–0.05 mg/dm3) in nine samples. In general, the content of toxic metals in the samples does not exceed the permissible levels governed by technical regulations.

 

 

Using NMR analysis, the composition of the aqueous extracts of pot marigold inflorescence of cultivars “Geisha”, “Mahrovy 2000”, “Dragon”, “Prince of India” were investigated. Inflorescences of pot marigold were used for the analysis. Plants were grown in the experimental area of the Department of Biochemistry and Biotechnology of Plants of Central Botanical Garden of the NAS of Belarus. Inflorescence of “Mahrovy 2000” was collected in July 2013–2016, other varieties – in 2016. The raw materials were air dried and kept in the dark, then crushed in an agate mortar or in a coffee grinder. The extraction was performed with distilled and deuterated water (D₂O) at a ratio of plant raw material : extractant = 1 : 15. As a result, the qualitative and quantitative composition of aqueous extracts of cultivars was determined. In the investigated samples 11 aminoacids: alanine, γ-aminobutyric acid, asparagine, valine, glutamine, isoleucine, leucine, proline, tyrosine, threonine and phenylalanine were determined, asparagine and proline prevailed. Monosaccharides, such as 2 isoforms of glucose and 3 isoforms of fructose, were determined as well. Analysis of the spectra on 31Р showed that phosphate is present in significant amounts in the aqueous extract of pot marigold flowers. “Geisha”, “Mahrovy 2000” and “Prince of India” varieties were shown to have similar qualitative and quantitative composition of carbohydrates and sugars. Spectrum of extracts of the variety “Dragon” was different from the others with the asparagine predomination in the pool of amino acids, and the content of β-fructopyranose lower in comparison with other varieties.

 

 

The convenient method for preparation of ethoxylated highly lipophilic quaternary ammonium salts has been developed, including alkylation of methyl gallate with dodecyl bromide, hydride reduction of ester group, introduction of the polyethoxylated fragment into the side chain, substitution of the terminal hydroxy group by chlorine and quaternization by a tertiary amine. The salts prepared possess the properties of ionic liquids and can be of interest as active components for ion selective electrode membranes.

Phosphorylated derivatives of amino acids: glycine, β-alanine, γ-aminobutyric, L-aspartic and L-glutamic acid have been synthesized. Phosphorylation reaction is carried out using dimethylphosphite on allyl ethers of N-acetyl derivatives of amino acids. Obtained phosphorylated amino acids are of interest for potential use as pharmaceutical substances for a new class of effective drugs.

 

 

A reagent kit EIA-TOXIN T-2 for the determination of mycotoxin T-2 toxin in feeds and foods by a direct competitive enzyme immunoassay using microtitration plate has been developed and tested. The evaluated parameters of the kit and metrological characteristics of the technique of measurements correspond to the modern level of immunoassay development and provide the determination of T-2 toxin content of agricultural products in a range of 30 to 1000 mg/kg with proper accuracy and precision.

Modern molecular diagnostics with polymerase chain reaction (PCR) is widely used as a basic tool for detection of various diseases and control of their course. Today the fluorescently labeled DNA-probes have the greatest popularity due to their high sensitivity and ease of use. Fluorescence intensity is the most important characteristic of fluorescently labeled DNA-probes. Increase of fluorescence intensity will enhance the sensitivity of analysis. Fluorescence intensity can be increased by multiple introduction of fluorophores based on special rigid linkers. Therefore the derivatives of 3,5-diaminobenzoic acid were used. In this paper we report on the synthesis of linkers based on 3,5-diaminobenzoic acid and their application in synthesis of the reagents with two fluorescein fluorophores and phosphoramidite or azide function for introduction of label into oligonucleotides. It is shown that obtained DNA-probes have almost twofold increase of fluorescence intensity and improved photophysical characteristics.

The results of shotgun proteomic analysis of microgram quantities of hepatocellular carcinoma cells (HepG2) are described. Identified is a number of proteins which have been reported to be biomarkers and therapy targets.

UV-induced graft polymerization of acrylic acid on the polypropylene film surface under high-power (750 mW/cm² ) irradiation from UV-LEDs was investigated. The maximum amount of grafted polymer was reached in 30 s, while using low-power irradiation (10–15 mW/cm² ) takes tens of minutes for the same amount of product. IR FTIR spectroscopy with different radiation penetration depth reflection elements of ZnSe–45° и Ge–45° showed the grafted polymer to be formed in a thin surface layer without any significant insertion throughout the film. Contact angle for water showed a minimum (21°) at 15 s of UV-irradiation time at small amounts of grafted polymer.

 

The complex of geochemical barriers in soils of a carbonate range significantly affects accumulation and profile distribution of the majority of the studied heavy metals and minerals. Within combined alkaline-carbonate barrier of the BS_Ca horizon, the migratory mobility of such dangerous heavy metals as Pb, Zn, Cd, Ni is sharply limited. At the same time, migratory activity and danger of accumulation in plants of Cr and partly Mn remains.

 

The introduction of triethanolamine into conversion of potassium chloride and calcium sulfate was found to promote the formation of potassium sulfate on a reaction: 2KCl + CaSO₄∙2H₂O → K₂SO₄ + CaCl₂ + 2H₂O, while in a water media this process consists of two stages. On the first stage syngenite is formed, while on the second stage К₂SO₄·CaSO₄·H₂O is decomposed with a formation of potassium sulfate as follows: 2KCl + 2CaSO₄∙2H2O→ K₂SO₄·CaSO₄·H₂O + CaCl₂ + H₂O, K₂SO₄·CaSO₄·H₂O → K₂SO₄ + CaSO₄ + H₂O. The optimal conditions of realization of reaction (1) in presence a triethanolamine are found. For this process to be fulfilled, the 60% concentration of triethanolamine is necessary, with the norm of КС1 flow of 140-160% from stoichiometry and a 3 h of agitation at the rotation speed of 350 turns/min. At these conditions the content of К₂SO₄ in the prepared product is 91–93 % and the utilization factor of potassium ion is 90–92%.

 

One of the important ways to increase the efficiency of purification of groundwater is a search for new materials with greater selectivity and catalytic activity for removal of iron and manganese ions. Today, the following materials are most widely used as a load: quartz sand, anthracite and others. The anthracites were selected as research object. The anthracite pellets were coated with iron and manganese oxides by exothermic combustion in a muffle furnace and microwave furnace. The elemental composition of the surface of the obtained materials was investigated. The results of comparative analysis of the obtained materials in comparison with the initial anthracite for cleaning groundwater from iron and manganese are presented. A number of conclusions about the effectiveness of the obtained materials were made based on the experimental studies conducted on the water utilities

The development of electrical products with increased technical and economic indicators requires further improvement of electrical insulating materials. Due to the wide introduction of automatic winding methods, it is of great importance to develop varnish coatings that ensure the reliability of insulation under significant mechanical stresses. This study was devoted to the development of the operational properties of electrical insulating varnishes by developing technologies for high-efficiency secondary products of terpenomaleinic resins (TMS resins) and thermosetting compositions based on them. In this work, physical and chemical properties of TMS resins modified with heavy metal salts such as acid number (AN, mg of KOH/g), softening temperature (T_s, °C), viscosity (v²⁰) and destruction temperature (T_d, °C) were studied. The effect of the obtained TMS resins on physical and mechanical properties of lacquer coatings based on them such as film thickness (μm), hardness of the varnish coating (conventional units) and the corrosion resistance was studied. The effect of TMS resins modified with salts of heavy metals (Co, Mn and Zn acetates) on physical and mechanical properties of lacquer coatings based on them was studied as well.

 

Overview of the main experimental results in the field of applied enzymology of phosphatidacylhydrolases in a study of the structure – function relationship in the process of a phospholipolysis including soluble (hemoglobin), peripheral (b₅), integral (CYP2B4) and anchor (CYP3A4) proteins, as well as low-molecular bioregulators (chlorine- and phosphoorganic compounds, derivatives of 1,3-cyclohexanedione, oxazole, the tiotetronic and fatty acids). The strategic prospects of development of scientific research and innovation within bioorganic chemistry at the field of applied (engineering) enzymology involving phospholipolytic enzymes, are discussed.