Essentially new method of definition of specific surface of micropores of micromesoporous adsorbents based on determination of side surface of a pore which is blocked by adsorbate molecules placed in her cross-section is proposed. Justification of the method is carried out and an opportunity of its practical application at estimation of a specific surface of the porous bodies containing micropores is shown. Limitation of the BET methods for definition of a specific surface of microporous and micromesoporous materials is shown. It is emphasized, that applicability of the BET method for analysis of adsorption processes is restricted by the relative adsorbates pressure of 0.05–0.35.

A method for simultaneous determination of thiuram D and E in aqueous extracts in the sanitary-chemical analysis of rubber by high performance liquid chromatography has been developed. Separation was performed using column Hypersil Gold 250 mm, internal diameter 4.6 mm, graining phase 5 μm, a mixture of acetonitrile–bidistilled water (80 : 20 v/v) was used as a mobile phase at a flow rate of 0.4 ml·min−1, UV detection was at 280  nm. The chromatographic parameters such as retention times, peak asymmetry, resolution factor and selectivity factor, have been determined. It has been shown that the method is linear in the range of 0.005 mkg/ml – 0.05 mkg/ml. Using the calibration curve and standard deviations analytical signal, limits of quantification have been calculated, being 0.003 mkg/ml and 0.004 mkg/ml for thiurams  D and E, respectively. It has been found that the difference between values of the average result variances of two samples obtained under conditions of intermediate precision in determining the content of thiuram D and thiuram E in model samples, is insignificant. The developed method has been tested in the sanitary-chemical analysis of sample toys and medical products from rubber.

La2-xSrxNiO4-δ (x = 1.0–1.6) nickelates were evaluated as potential cathode materials for solid oxide fuel cells, with focus on the structural stability, oxygen nonstoichiometry and electrical conductivity under oxidizing conditions. All studied ceramic materials were found to preserve K2NiF4-type tetragonal structure under oxidizing conditions at 25–900  °С.
La2-xSrxNiO4-δ (x = 1.0–1.6) nickelates demonstrate oxygen deficiency at temperatures above 500 °С, with oxygen nonstoichiometry increasing with temperature and strontium content. The electrical conductivity is p-type and show metallic-like behavior under oxidizing conditions at 500–1000 °С. The highest conductivity values, 220 S/cm at 900 °С and 440  S/cm at 600 °С in air, are measured for La0,8Sr1,2NiO4-δ ceramics. While the high-temperature XRD studies revealed strongly anisotropic thermal expansion of La2-xSrxNiO4-δ crystal lattice, the lattice volume show nearly linear dependence on temperature, with average linear thermal expansion coefficients varying in the range (14.2–15.6) · 10-6 K-1.

A new anion exchanger with aminoethylpiperazine functional groups has been synthesized from polyacrylonitrile fiber. The subsequent alkylation with epichlorohydrin afforded another anion exchanger with strong base functional groups. The optimal conditions for synthesis of these ion exchangers have been found, their physical chemical and sorption properties have been investigated. Experimental data of sulfur dioxide sorption on the ion exchanger with aminoethylpiperazine functional groups show its practical applicability for air purification from acidic pollutants.

The article describes synthesis of isoxazol- and isothiazol- containing esters, diesters, amides and diamides. The derivatives with different 1,2-azole moieties in one molecule were obtained. Compounds synthesized are promising as ligands for complexes with palladium(II) and other transition metals and subsequent study of their catalytic properties.

Most analytical methods in metabolomics allow determination of relative intensities or require several internal standards of metabolites. For quantitative analysis, determination of absolute concentrations is required. For this purpose, the gas chromatography/tandem mass spectrometry methods are used, based on methyl chloroformate derivatization and quantification by spiking samples with metabolite standards separately derivatized with deuterated derivatization reagents. Described herein is the synthesis of deuterated methyl chloroformate – the reagent for absolute quantitative metabolite analysis by gas chromatography-mass spectrometry. The method allows preparation and isolation of deuteromethylchloroformate with high yields.

Fluorinated nucleosides have been shown to possess interesting physicochemical and biological properties. Bioisosteric replacement of a hydroxy group or a hydrogen atom by fluorine atom(s) is a classic approach in medicinal chemistry
to improve the pharmacological properties of a biologically active molecule. Essential modifications that led to the discovery of fluorinated nucleosides with biological activity are substitutions at 2′- and 3′-positions deoxy-furanosyl moiety. Novel 6-azathymine 2′(3′)-fluorodeoxy nucleosides have been prepared by the silyl method starting from persilylated 6-azathymine and 1-O-acetyl-2,5-di-O-benzoyl-3-deoxy-3-fluoro-α,β-D-ribofuranose or 3,5-di-O-benzoyl-2-deoxy-2-fluoro-β-D-arabino-furanosyl bromide. Debenzoylation of protected 6-azathymine 2′(3′)-fluorodeoxy nucleosides with methanolic ammonia resulted in the corresponding fluorinated nucleosides in good yields. Along with the main products of the deprotection, their 5′-O-benzoyl derivatives were isolated. Conversion of the 6-azathymine 2′(3′)-fluorodeoxy nucleosides into 5-methyl-6-azacytosine 2′(3′)-fluorodeoxy nucleosides was accomplished via the corresponding 4-thioderivatives. The structures of all synthesized nucleosides were proved by UV-, NMR- and mass-spectroscopy. Novel 6-azapyrimidine 2′(3′)-fluorodeoxy nucleosides are of interest as potential antiviral and anticancer agents.

Synthesis of 2,2′-dihydroxybiphenyl-4,4-dicarboxylic acid by alkaline fusion of 1-nitro- and 1-methoxy substituted 5,5-dioxodibenzothiophene-3,7-dicarboxylic acids has been investigated. It has been shown that along with dibenzothiophene ring opening and formation of biphenyls, a cyclization reaction also occurred. Small amounts of dibenzofuran-3,7-and 4-hydroxycarbazole-2,7-dicarboxylic acids have been found among products of the reaction. New luminescent dyes based on 2,2′-hydroxybiphenyls have been synthesized.

Biphenyl derivatives containing 5-tetrazolyl moiety in position C4 and C4′ position of aromatic rings were synthesized by reaction of 1,3-dipolar cycloaddition. Biphenyl derivatives with 1-tetrazolyl moiety in the C2, C4 and C4′ position of aromatic rings were prepared by reacting the corresponding amines with orthoformic ester and sodium azide. The physicochemical spectral characteristics and fungicidal activity of the synthesized compounds were studied. The sensitivity of the pathogenic fungus Botrytis cinerea, Fusarium sp., Penicillium sp., Alternaria sp., Colletotrichum sp. against isomeric 4, 4′-tetrazolyl biphenyl derivatives was investigated. Tests have shown that the 5-tetrazolyl biphenyl poseses a much stronger inhibitory effect on the growth of pathogenic fungi than 1-tetrazole isomer. The phytotoxicity studies and influence of additional hydrophilic and hydrophobic groups in the biphenyl moiety were investigated for 4,4-di (1H-tetrazol-5-yl)-
biphenyl and 2-substituted derivatives. The strongest fungicidal effect was observed for 0.1 % solutions of samples of 4,4′-di (1H-tetrazol-5-yl) -biphenyl-2-ol and 5,5′- (2- (hexyloxy) biphenyl 4,4′-diyl) bis (1H-tetrazole). The optimum balance of high fungicidal activity and low phytotoxicity determined for 5,5′- (2- (hexyloxy) biphenyl-4,4′-diyl) bis (1H-tetrazole).

The EIA-ZEARALENONE reagent kit for the determination of zearalenone mycotoxin in feed and food by direct ELISA using microtitration plate has been developed and tested. The evaluated technico-analytical 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 zearalenone content in agricultural products in a range of 50 to 800 mg/kg with proper accuracy and precision.

The structure of macromolecular complexes of microelements (copper, cobalt) with copolymers of acrylamide and sodium acrylate has been shown by 13C  NMR spectroscopy to include only the carboxylate functional group of the macromolecule as a ligand. The stoichiometry of the complexes studied could not be determined by 13C NMR spectroscopy due to a high lability of the complexes. In determining the qualitative structure of macromolecular complexes by 13C  NMR spectroscopy experimental conditions (primarily the concentration ratio of the functional groups of the copolymer involved in the complexation, and metal ions) must be selected considering a paramagnetism value of the metal ion. It was found that the solution’s pH influences on the interaction of copper ion with a carboxylate group of the copolymer to form a macromolecular complex. Interaction increasesin the transition from the neutral to acidic (pH  5) medium, and complex practically not formed in alkaline medium (pH 9).

The prospects of the energy and technology use of biomass in the world and in the Republic of Belarus are considered, the comparative analysis of ways of its thermochemical degradation is performed, the experimental studies of the pyrolysis of mixed compositions with peat are presented.

Under the laboratory conditions, processes of flocculation, phase separation and structurization of saline clay dispersion have been simulated and investigated. Effect of polymer (polyacrylamide) introduced at flocculation stage on properties of final products was studied. It has been found that at polymer concentrations of 0.01–0.2 mg/g, solid phase density and dewatering capability of flocs increase 1.4–1.6 times. Strength yield stress and optimal granules size have a maximum at polyacrylamide concentration of 0.2 mg/g of the disperse phase. Introduction of polyacrylamide into saline clay dispersion during structurization step reduces yield stress, density and plasticity 1.4–1.7 times, compared to adding the polymer at flocculation stage. This could be explained by adsorption of polymer macromolecules on the clay particles during flocculation step, to form bridges, whereas during structure formation step polymer binds larger clay aggregates and the strength of such contacts is weaker.
Results of the study allow to estimate a concentration range of polymeric flocculant which provides optimal parameters of the studied processes and properties of the final products. The results are used in the complex recycling technology of clay-containing wastes of potash production.

The review is devoted to terpenoid-maleic adducts and their derivatives. Terpenoid-maleic adducts find wide application in various industries. In this review, the ways of adducts’ preparation, their properties, afterproducts on their basis and application in various compositions are discussed. Levopimaric and abietic rosin acids, turpentine components, terpene hydrocarbons, solid turpentine polymers and rosin oils formed in production of rosin and its glycerol ester, have been used as raw materials for production of adducts.