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CHEMISTRY

ISSN 2227-6017 (ONLINE), ISSN 2303-9868 (PRINT), DOI: 10.18454/IRJ.2227-6017
ПИ № ФС 77 - 51217, 18+

USAGE OF SOLID-PHASE EXTRACTION METHOD FOR PURIFICATION OF 16-α[18F]FLUORINE-17β-ESTRADIOL, A RADIOTRACER FOR PET DIAGNOSTICS OF BREAST CANCER

Posted in 2018, CHEMISTRY, Issue №6(72) June 2018 | 0 comments

A new method of solid-phase extraction (SPE) for the purification of 16α-[18F]fluorine-17β-estradiol ([18F]FES), radiopharmaceutical (RPC) for PET diagnostics of estrogen-positive (ER +) breast cancer is proposed. [18F]FES was obtained by nucleophilic radiofluorination of the cyclic sulfanyl precursor MMSE with subsequent deprotection by hydrolysis in an acidic medium. In order to separate [18F]FES from the reaction mixture by SPE method, disposable cartridges based on various sorbents have been studied. It was shown that the use of the OASIS WAX 3cc cartridge is the most effective and allows to obtain [18F]FES with radiochemical purity > 99% and the residual content of MMSE and chemical impurities of 2-5 μg/ml, which allows using this RPC in preclinical and clinical studies. The content of ethanol in the injection form of the drug is 5%, which meets the requirements of the State Pharmacopoeia. The advantage of the new cleaning method is simplicity, speed (40 min) and the possibility of automation in modern synthesis modules. The use of disposable SPE cartridges at the purification stage meets modern GMP requirements.

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POLYMER COATINGS FOR PROTECTION OF HEAT-EXCHANGE TUBES OF VAPOR CONDENSER AGAINST CORROSION AND SALTATION

Posted in 2018, CHEMISTRY, Issue №5(71) May 2018 | 0 comments

Fundamental physical and chemical processes on metallic heat-exchange surfaces cause the interconnection of the processes of scale depositing and corrosion. The usage of polymer coatings on the inner surface of the heat-exchange tubes promotes the decreasing of scale depositing and prevents corrosion. Laboratory studies and complex examination of the corrosion state and scale depositing showed that ROCOR polymer coatings proved to be more effective anticorrosive protection having antiscaling action with industrial experience of 12 years.

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DETERMINATION OF PARAMETERS OF UNIT CELLS AND ELECTROPHYSICAL PROPERTIES OF COMPLEX OXIDES IN CaSnSiO5 – YFeTiO5 SYSTEM

Posted in 2018, CHEMISTRY, Issue №5(71) May 2018 | 0 comments

Solid solutions with the general formula Ca1-xSn1-xTixSi1-xYxFexO5 were synthesized in the low-temperature plasma of hydrogen-oxygen flame (LTP). The chemical composition of the samples in the “x” interval varied from 0 to 1.0 in the experiments. Depending on the chemical composition, the parameters of the crystallographic lattice were determined. It was found that at a temperature of 1170 K the CaSnSiO5–YFeTiO5 system consists of two homogeneous phases with wide homogeneity regions. The pycnometric densities and electrophysical characteristics of the samples were measured: the electrical conductivity (σ), the band gap (ΔE), the permittivity (ε), the molar polarization (P), and the molecular polarizability (α). It is established that all the compositions studied are dielectrics with a semiconducting character of electrical conductivity.

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EPOXY MATERIALS DILUTED BY WATER FOR ANTI-CORROSION PROTECTION OF CONSTRUCTION STRUCTURES IN ADVERSE CLIMATIC CONDITIONS

Posted in 2018, CHEMISTRY, Issue №5(71) May 2018 | 0 comments

A new generation of environmentally friendly protective waterborne epoxy coatings has a combination of significant advantages over traditional water-dispersible compositions. Long-term use in industrial conditions and extended climatic tests in the temperate cold, marine and tropical climates have shown that waterborne epoxy couches and enamels are resistant to freezing at – 40°C, do not contain volatile components with a sharp chemical odor, temperatures, ultraviolet and retain decorative properties in an acceptable color range.

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DIFFUSION OF PHOSPHONIC INHIBITORS FOR SCALE FORMATION IN EPOXY MATRIXES

Posted in 2018, CHEMISTRY, Issue №4(70) April 2018 | 0 comments

The transfer of solutions of phosphorus-containing scale forming inhibitors in epoxy coatings was studied. It is shown that the diffusion distribution profiles of phosphonic acids have a discontinuous front view characteristic of a mineral and organic acids. The penetration rates of λ phosphonic acids are comparable to that characteristic of inorganic acids, in particular, phosphoric acids. The acid/water ratio in the internal solution in the polymer is higher than in the external solution of the diffusant at the diffusion of phosphonic acids into epoxy matrices having ion-exchange properties.

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MATERIALS OF FUTURE

Posted in 2018, CHEMISTRY, Issue №2(68) February 2018 | 0 comments

The most perspective and actively used groups of “smart” materials and the origin of the term itself are considered in the paper. The basic properties, the methods of development and application of “smart” materials are indicated, their multi-functionality is established. The theoretical basics and the experiment on development of supramolecular materials by the scientists of Munich Technical University are given. The results of this study are analyzed, and the conclusion is as follows: the use of supramolecular hydrogels in relation to the living organism is limited.

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ANTIOXIDANT ACTIVITY OF INHIBITORS IN OXIDIZATION OF PINANE HYDROPEROXIDE

Posted in 2018, CHEMISTRY, Issue №1(67) January 2018 | 0 comments

The need to improve the quality of motor fuels through the introduction of additives is shown in the paper. The urgency of developing new antioxidants and determining their effectiveness has been revealed. The mechanism of hydrocarbon oxidation is described. Experimental studies of the kinetics of its decomposition in the presence of inhibitors of peroxide reactions were carried out on the example of a model substance (pinane hydroperoxide). It was established that all studied inhibitors significantly, with varying degrees of activity, increase the stability of the model substance.

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COMPARISON OF IMMOBILIZATION METHODS OF PROTEOLITHIC BACILLUS SUBTILIS COMPLEX ON CHITOSAN

Posted in 2018, CHEMISTRY, Issue №1(67) January 2018 | 0 comments

The methods of activation of the matrix – high molecular weight chitosan for subsequent immobilization of enzymes of a proteolytic complex from Bacillus subtilis are investigated. Benzoquinone, glutaraldehyde and epichlorohydrin are used for the activation reaction. It is shown that the use of glutaraldehyde in the technology for the activation of the technology allows obtaining preparations of immobilized enzymes with a higher specific activity and lower losses. The technological parameters of synthesis of preparations of immobilized proteases were chosen.

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ТРАНСФОРМАЦИЯ ДИМЕТИЛФЕНОЛОВ В ПРИСУТСТВИИ ВОДНЫХ РАСТВОРОВ Р-Мо-V ГЕТЕРОПОЛИКИСЛОТ: 2. МЕХАНИЗМ РЕАКЦИИ

Posted in 2017, CHEMISTRY, Issue №12(66) December 2017 | 0 comments

Окисление диметилфенолов в соответствующие пара-хиноны важно с точки зрения их дальнейшего применения в различных важных областях науки. В статье описаны основные этапы трансформации 2,3- и 2,6-диметилфенолов в соответствующие пара-бензохиноны в двухфазных системах в присутствии водных растворов Р-Мо-V гетерополикислот, установленные в ходе детального анализа экспериментальных данных. Найденные закономерности могут быть использованы для расширения круга потенциальных субстратов и упрощения оптимизации реакционных условий.

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OXIDATIVE TRANSFORMATION OF NATURAL COMPOUNDS UNDER CONDITIONS OF INTER-PHASE CATALYSIS

Posted in 2017, CHEMISTRY, Issue №12(66) December 2017 | 0 comments

The problem of complex processing of renewable raw materials using environmentally safe and low-waste technologies is now becoming increasingly important. Natural compounds are convenient objects for oxidative transformation with the production of a number of practically important substances. The use of bi-functional catalysts based on peroxypolyxometallates in combination with quaternary ammonium cations is a promising direction for carrying out the reaction of hydrogen peroxide oxidation of desaturated compounds of natural origin such as desaturated fatty acids, terpenes and benzopyrones.

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CHEMICAL MODIFICATION OF SUNFLOWER OIL

Posted in 2017, CHEMISTRY, Issue №12(66) December 2017 | 0 comments

The paper considers the possibility of chemical modification of sunflower oil in various systems. Oil is obtained from bleaching earth after refining. The composition of vegetable oils is studied by means of IR spectroscopy and chromatography. The most efficient conditions for the chemical modification of sunflower oil are identified. While studying the oxidation process of vegetable oil, the kinetics of change in functional groups which is prone to polymerization is shown. The oxidation and polymerization processes are confirmed by IR spectroscopy.

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ABOUT DEVELOPMENT PRIORITIES OF TECHNOLOGY AND PROCESSING OF ELASTOMERS

Posted in 2017, CHEMISTRY, Issue №12(66) December 2017 | 0 comments

The paper presents a brief history of technology and processing of natural rubber from origin to the contribution of France, Russia and the USA in its development. The features of the development of technology and processing of elastomers during the world wars of the 20th century are analyzed as well. The relationship between the weakening of postwar US sanctions for the period of introduction of furnace black carbon in the USSR with prohibitions on the publication of research results on the properties of its highly structured porous grades for antistatic rubbers is established. The features of the postwar development of technology and the processing of elastomers in the US and modern Russia are analyzed.

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FRACTIONATION, CHARACTERISTICS AND USE OF MEMBRANE FRACTION OF GLUCONOBACTER OXYDANS BACTERIA

Posted in 2017, CHEMISTRY, Issue №12(66) December 2017 | 0 comments

The paper presents the method for obtaining membrane fractions of Gluconobacter oxydans bacteria for the use in biosensors and biofuel elements. The activity of the enzyme preparation with the use of the quinoneimine dye of 2,6-dichlorophenolindophenol (2,6-DXFIH) is determined by a spectrophotometric method. It is established that the increase in the centrifugal acceleration up to 101000g enables a more complete deposistion of membrane fractions of the Gluconobacter oxydans bacteria, and the obtained enzyme preparation has the greatest activity in relation to the oxygen consumption, which makes it a more effective biocatalyst.

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POTENTIOMETRIC DETERMINATION OF “AVAILABLE CHLORINE” IN ELECTROCHEMICALLY TREATED CHLORINATED ELECTROLYTES

Posted in 2017, CHEMISTRY, Issue №12(66) December 2017 | 0 comments

The most of analyses of residual available chlorine are carried out by traditional chemical technique based in the methods of volumetric titration by means of working solution of sodium thiosulphate with visual indication of equivalence point on starch. The main disadvantages of the methods are low chemical stability of sodium thiosulphate solutions, necessity of periodic control of titre, high limit of available chlorine content and therefore low sensitivity of the technique and relatively significant error of determination. That research work on developing instrumental methods of available chlorine control is carried out. Its purpose is to eliminate the disadvantages of classic volumetric analysis, to automatize it and reduce labour intensity. Variant of indirect potentiometric method for determination of total content of active chlorine in electrochemically treated electrolytes, containing chlorine, without the use of a buffer system proposed.

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TRANSFORMATION OF DIMETHYLPHENOLS IN THE PRESENCE OF AQUATIC P-Mo-V SOLUTIONS OF HETEROPOLYACIDS (HPA) AND THEIR ACID SALTS

Posted in 2017, CHEMISTRY, Issue №11(65) November 2017 | 0 comments

High speed and selectivity of substrate oxidation plays an important role in two-stage catalytic processes of oxidation of organic substrates in the presence of solutions of P-Mo-V heteropolyacids (HPA) achieving a high rate of catalyst regeneration. For these purposes, it is promising to estimate the possibility of using solutions of acidic salts of HPA that have a reduced acidity in comparison with the solutions of the initial HPA when the regeneration of the solution is accelerated. A series of acid salts of the P-Mo-V HPA of the Keggin structure was studied in the oxidation reactions of 2,3- and 2,6-dimethylylphenols to determine the effect of the HPA degree of substitution on the selectivity of the processes.

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SYNTHESIS OF NEW SCHIFF BASIS AND BISAMINOPHENOL FROM LEVOPYMARIC ACID

Posted in 2017, CHEMISTRY, Issue №11(65) November 2017 | 0 comments

The available optically pure diterpenes, levopimaric acid, is used as a chiral natural raw material for the preparation of enantiomerically pure diamine and Schiff basis. The synthesis is based on the conversion of the fumaropimaric acid monomethyl ester to optically pure trans-1,2-diamine through the Curtius rearrangement, while maintaining the configuration of the chiral centers. By the interaction of chiral diamine with salicylic aldehyde, bisaldimine is obtained, the reduction of which led to the production of trans-1,2-bisaminophenol.

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ASSOCIATES OF NANO-DIMENSIONAL PALLADIUM ON THE SURFACE OF SILICON

Posted in 2017, CHEMISTRY, Issue №11(65) November 2017 | 0 comments

The following paper studies the features of the chemical deposition of palladium nanostructures in liquid medium. Monocrystalline silicon is used as the target substrate. To obtain a greater homogeneity of the nanostructures, the modification of the silicon surface by aminosilanes is considered. The structure and topography of the resulting surface is visualized and studied by the methods of atomic force microscopy. The elemental composition is confirmed by X-ray fluorescent microanalysis. As a result, it is possible to obtain an array of densely located palladium particles with a small spread in size (90-150 nm) and the same shape.

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STUDY AND SELECTION OF REAGENTS IN THE DEVELOPMENT OF WATER-COLLOID CONNECTION COMPOUNDS FOR FOUNDRY CERAMICS

Posted in 2017, CHEMISTRY, Issue № 10(64) October 2017 | 0 comments

The manufacturing of metal parts of complex construction, having semi-closed internal cavities with a specific topology is carried out mainly with the use of the method of casting into ceramic molds. One of the main factors affecting the production of a quality casting is the quality of the ceramic shell (CS). The quality of a ceramic form largely depends on the materials used in its production and the properly selected reagents, which are surface active agents (surfactants) wetting agents, defoamers, organic glues, being the part of the ceramic suspension. The paper presents the results of the study of surface activity and selection of some wetting agents and defoamers used for the preparation of water-colloidal binder casting ceramics.

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SYNTHESIS OF BENZYLIDENEPHENYLENEDIAMINES BASED ON M-PHENYLENEDIAMINE AND SUBSTITUTED BENZALDEHYDES

Posted in 2017, CHEMISTRY, Issue № 9(63) September 2017 | 0 comments

In the course of research, low-temperature condensation of substituted benzaldehydes and meta-phenylenediamine in ethyl alcohol medium with quantitative yields produced soluble and fusible benzylidene-phenylenediamines containing azomethine groups. The structure of obtained benzylidene-phenylenediamines was confirmed by spectral methods and elemental analysis. It is found that when luminous benzylidenephenylenediamines are irradiated by means of UV light, they exhibit luminescent properties. Synthesized benzylidenephenylenediamines can be used as monomeric substances for oxidative polymerization, as well as for the synthesis of luminescent rigid-chain polymers.

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QUANTUM CHEMICAL STUDY OF HYDROGEN BOND AND SPATIAL STRUCTURE OF CONFORMATIONS OF THIO-DERIVATIVES OF ACETYLACETONE

Posted in 2017, CHEMISTRY, Issue № 7(61) July 2017 | 0 comments

In order to study the energy of the hydrogen bond and the effect of the calculated bases in the framework of the non-empirical approach, we estimated the conformational structures of the enolisated forms of thioacetylacetone in one-electron methods taking into account the electron correlation by the methods of the Möller-Plesset perturbation of the second order (MP2) and the electron density functional (DFT). It is shown that the electron correlation effect and the expansion of the basis for the one-electron method can significantly affect the qualitative picture of the energy of conformers and tautomers.

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