Search articles

This is an open access article distributed under the terms of Creative Commons Attribution 4.0 International License (CC-BY 4.0).

Phase equilibria and salting out of butyric acid in the ternary system potassium nitrate + water + 2-(2-butoxyethoxy)ethanol

Authors: Smotrov M. P., Godyaeva M. V., Hrykina A. V., Cherkasov D. G.

Visual polythermal method in the bynary system of water-2-(2-butoxyethoxy) ethanol in the range of –25÷0° C the ice melting line is determined and the phase equilibria in the ternary system potassium nitrate–water–2-(2-butoxyethoxy) ethanol are studied in the range of 10.0–90.0° C. The ice melting line in the water–2-(2-butoxyethoxy) ethanol binary system is a flat, smooth line. This form of the melting line shows a hidden separation in liquid mixtures.

Destruction of the active substance of tetracycline under the action of UV irradiation

Authors: Ustinova M. N., Zhunusov N. S.

The growth of the pharmaceutical industry inevitably leads to an increase in the concentration of organic pollutants in environmental objects. The problem of inactivation of such pollutants and water treatment is extremely urgent. The aim of this work was to use combined chemical methods of destruction of tetracycline, as one of the most commonly used antibiotics. The destruction of the active substance of tetracycline under UV irradiation, UV irradiation in the presence of hydrogen peroxide, and UV irradiation in the presence of hydrogen peroxide and ferrous iron ions was studied.

Synthesis of polysubstituted spiropyrrolidines using 2-acetylfuran, 2-acetylthiophene, and 2-acetylpyrrole

Authors: Borisova S. V., Sorokin V. V.

 A series of novel spirooxindoles have been synthesized through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and sarcosine with the dipolarophile 3-phenyl-1-(heteroaryl -2-yl)prop-2-en-1- one, synthesized by the Knoevenagel reaction using 2-acetylfuran, 2-acetylpyrrole, 2-acetylthiophene and substituted benzaldehydes. These compounds are used for the first time as dipolarophiles.

Express determination of cephalexin

Authors: Tumskaia A. V., Kosyreva I. V.

Test means based on immobilized Fehling’s reagent for the determination of cephalexin have been obtained. Methods for visual and colorimetric assessment of antibiotic concentration using a smartphone camera have been developed. The optimal conditions for the indicator reaction have been selected with varying heating time and temperature. For a visual semi-quantitative assessment of the content of cephalexin, a color scale has been obtained.

Determination of thymol with micellar extraction preconcentration

Authors: Tsygulyova E. I., Doronin S. Y.

For the efficient preconcentration of azo compounds – products of the interaction of 4-nitrophenyldiazonium with thymol, a system 4-nitroaniline (4-NA) – NO2 - – Triton X-100 – NaOH – ethanol has been proposed. The optimal conditions for the formation of micellarsaturated phases of the system under study have been established: 3. 10-4 M 4-NA – 3. 10-4 M NO2 - – 5% Triton X-100 – 2.8 M NaOH – 10 vol. % С2Н5ОН. A spectrophotometric study of the above system has been carried out.

ISE on Vitamin B6

Authors: Varygina O. V., Chernova R. K., Сusina E. F.

Sensor obtained by ion associate of vitamin B6 with tetraphenylborate ion and determined its electrochemical characteristics. Method biionnyh potentials determined selectivity coefficients of the electrode. The method of determination of the main substance in the product «Pyridoxine hydrochloride».

Simultaneous Determination of Fungicides ThIuram and Tebuconazole in Grain by High Performance Liquid or Micellar Electrokinetic Chromatography

Authors: Amelin V. G., Tretyakov A. V., Bolshakov D. S., Lavrukhin D. K.

Optimal conditions for separation and determination by HPLC or MEKC combined fungicides thiuram and tebuconazole are selected. The method of simultaneous determination of pesticides in grain offered. The recovery of pesticides was 90–95%. Lower bounds defined by the contents of pesticides, taking into account the concentration amounted to 0.005 mg kg−1 in the MEKC method, and 0.0025 mg kg−1 in the method of HPLC. The relative standard deviation of the results of the analysis is less than 0.09, analysis of the duration of 1–1.5 h.

Luminescent Determination of Polycyclic Aromatic Hydrocarbons on Cellulose Diacetate Matrix Modified by Surfactants

Authors: Strashko A. V., Gubina T. I., Shipovskaya A. B.

The ability of using cellulose diacetate (CDA) as matrix for luminescent determination of polycyclic aromatic hydrocarbons (PAH) in aqueous media was studied. PAH sorption was carried out on the example of pyrene from water solutions. Cellulose diacetate matrix was modified by anionic and cationic surfactants - sodium dodecylsulphate (SDS) and cetyltrimethylammonium bromide (CTAB). The comparative analysis of dependence of fluorescence intensity and polarity index of pyrene was carried out.

Study Phase Triangles LiNO3 – NaNO3 – NaI, LiNO3 – KNO3 – KI and LiNO3 – RbNO3 – RbI Ternary Mutual Range Systems Li,M || I,NO3 (M – Na, K, Rb)

Authors: Maltseva A. V., Gubanova T. V., Garkushin I. K.

By differential scanning calorimetry (DSC) was first investigated experimentally determined complexes and phase characteristics of equilibrium points of the invariant three-phase triangles reciprocal systems of several Li,M || I,NO3 (M – Na, K, Rb). The compositions of eutectic (mol%) Li,Na || I,NO3 : (E1 ) NaNO3 – 42,5%, NaI – 5,0%, LiNO3 – 52,5% with a melting point of 178 °C. Li,K || I,NO3 (E2 ) LiNO3 – 44,0%, KI – 2,0%, KNO3 – 54,0% (mol) with a melting point of 117°.

Influence of Some Factors on Phase Separation of System Sodium Dodecyl Sulfate – H2O

Authors: Chernova R. K., Shestopalova N. B.

The isothermal behavior of systems SDS – H2 O and SDS – H2 O – electrolytes has been investigated in the range 0–100 °C. The effect of the addition of sodium chloride, salicylic acid and sodium salicylate on the nature of phase transitions was shown. The viscosity of aqueous solutions of SDS (0–30 wt. %) was studied. The view about the nature of possible self-assembled structures in the systems was expressed.

Description of the Chemikal Interreacting in the Quaternary Mutual Sistem Li,K||F,MoO4 ,WO4

Authors: Radzihovskaia M. A., Garkushin I. K., Danilushkina E. G.

The quaternary mutual system Li,K||F,MoO4 ,WO4 was partitioned into the simplexes and described the chemical interaction by conversion method and by method of ion balance. The prediction of the crystallizing phases conducted on the basis of the partition and of the equations for the reactions of conversion lines and for the method of ion balance.

Effect of Oil Sludge Filler on Physico-chemical Properties of the Bituminous Composite Materials

Authors: Kuzmina R. I., Shirokov I. P.

An elemental composition and particle size distribution of the solid residue oil sludge are investigated, and a test samples series of a composite material is performed. The physico-chemical and operational properties of this material are investigated. Found that the characteris tics of the resulting material allow to use it in production of bituminous concrete for road construction.

Quantum-chemical Research of the Mechanism of Reaction of an Acylating Butylmethylamine by Propionyl Chloride in the Presence of Lithium Hydride

Authors: Altuchov S. P., Nelga I. A., Medvetsky I. V., Komissarenko S. A., Aparkin A. M., Belousov E. B.

In this paper is presented quantum-chemical research of the mechanism of reaction of an acylating butylmethylamine by propionyl chloride in the presence of lithium hydride. The estimate of two basic synthetic paths of an acylating butylmethylamine is made. Prereactionary complexes, transient states and reaction products are computed in program PRIRODA by a density functional theory (DFT) in approximation PBE and basis L1. Activation energies of reactions are computed. 

Isolation and radiochemical purification of samarium isotopes using ion exchange resins АВ 17×8 AND KU-2

Authors: Salmenbayev S. E., Nurgaysinova N. K., Yessilkanov G. M., Temirzhanova А. E., Makarychev S. V.

The relevance of the research is caused by the need to develop a methodological base for determining 151Sm content in the soil cover of radioactively contaminated territories of Kazakhstan. The developed method for the determining of 151Sm will make it possible to assess the levels of soil contamination with this radionuclide, to determine the character of its spatial distribution, to allow estimating the internal exposure doses for the personnel and the population.

Synthesis and study of some properties of colloidal quantum dots of indium antimonide

Authors: Tsvetkova O. Y., Shtykov S. N., Zhukov D. N., Smirnova T. D.

Colloidal quantum dots of indium antimonide have been synthesized by a known technique. The shape and average diameters of quantum dots have been investigated by transmission electron microscopy using a transmission microscope. Controlling the size and shape of colloidal QDs provides information on the formation of the crystal structure of nanoparticles and their possible physical and optical properties. It has been found that InSb quantum dots are characterized by a polygonal shape.

Study of the diffusion process in films sodium salt of carboxymethyl cellulose – drug

Authors: Shurshina A. S., Kulish E. I.

The transport properties of medicinal films based on sodium salt of carboxymethylcellulose and the antibiotic amikacin sulfate have been studied in this work. It has been shown that the process of sorption of water vapor by such films and the release of a drug from them proceeds in an abnormal diffusion mode, which is explained by the slowdown of relaxation processes in glassy polymers, which include the sodium salt of carboxymethylcellulose.

Reuse of a purified solution of cetyltrimethylammonium bromide for the synthesis of gold nanorods

Authors: Gudova Y. D., Kochubey V. I., Skaptsov A. A.

We investigate the possibility of reusing CTAB solutions for repeated synthesis of gold nanorods. Three tasks have been solved. The first task is to clean the growth solutions from gold nanorods. The second task is to develop a method using a purified cetyltrimethylammonium bromide solution for repeated synthesis of gold nanorods with the same optical properties as in the initial synthesis. The third task is to test the possibility of management of the optical properties of nanorods during repeated synthesis.

The prospect of using Shewhart control charts in assessing the quality of ionometric measurements by the method of adding a sample to a standar

Authors: Shatunov V. M., Fokina A. I., Ashikhmina T. Y.

Modern methods of quantitative physical and chemical measurements should necessarily include procedures for quality control of research results. Recently, the procedure for quality control of measurements using control charts is gaining particular popularity in the practice of analytical measurements. To date, the methods of potentiometric studies operating in the territory of the Russian Federation, in most cases, do not include quality control using this control procedure.

Study of the relationship between geometric isomerism and biologically active properties of compounds

Authors: Gasanov A. G., Ayyubov I. G., Hajiyeva G. E., Qurbanova F. S.

The results of the research in the field of studying the relationship of the geometric structure of organic compounds with their biological activity are presented. It has been shown that the stereospecific structure of organic and inorganic molecules can have a direct effect on the biologically active properties of substances. Among the known types of stereoisomerism (geometric and optical), this work summarizes the effect of various types of geometric isomerism on the bioactivity of compounds. In addition, the results of the authors’ own research are presented.

Synthesis and structural features of 5-(4-bromophenyl)-3-((6-amino-2-mercaptopyrimidine)-4-amino))methylidene)-3Н-furan-2-one

Authors: Tikhomolova A. S., Mayorova O. A., Yegorova A. Y.

This work shows the possibility of synthesizing previously unknown 5-(4-bromophenyl)-3-((6-amino-2-mercaptopyrimidine)-4-amino)) methylidene-3H-furan-2-one containing a pharmacophore pyrimidine fragment by four-component one-pot reaction of malononitrile as the second methylene active component, thiourea, orthoester and 5-(4-bromophenyl)-3H-furan-2-one, which proceeds under mild conditions during thermal activation of the reaction mixture in isopropyl alcohol. Orthoester, as an electrophilic particle, makes it possible to introduce an additional carbon atom into the structure.

Pages