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Express Method for Cefazolin Determination in Small Samples Sensors Planar Potentiometric

Authors: Kulapina E. G., Chanina V. V.

The unmodified and modified by polyaniline and nanoparticles planar potentiometric sensors on the basis of tetradecylammonium associates with a complex silver (I) – cefazolin are created. Optimum ratios of components in carbon-containing ink are established: 30–32% carbon powder, 16–18% polyvinylchloride, 48–50% dibutylphthalate and 1–3% of electrode active compound (EAC). Planar sensors of two types are examined: electrode active compounds, electrode active compound and modifiers were added into in carbon-сontaining ink.

Application of the Sodium Arsenite Hydrolysed for Obtaining Pure Arsenic Products

Authors: Demakhin A. G., Akchurin S. V., Fedorov V. A.

The article presents information about the possibility of using sodium arsenite hydrolyzed as a new type of arsenic-containing raw material for obtaining marketable products of various qualities. The methods of purification of arsenic (III) oxide as the main product of sodium arsenite hydrolyzed processing to various degrees of purity (3-6N) are given, which allows using it as a raw material for the synthesis of a wide range of arsenic compounds: arsenic acid, elemental arsenic, arsenic trichloride.

Rare Earth Metal Iminodisuccinates

Authors: Makushova G. N.

Iminodisuccinates of several rare earth metals (REM) have been synthesized as a result of reaction between freshly prepared ammonia iminodisuccinate and REM chloride soltuions at pH 3. According to element analysis data, the chemical composition of synthesized salts is MeHC8H7O8N · nH2O, where Ме = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, n = 1–5. Synthesized compounds were further analyzed via X-ray diffraction and thermogravimetric analysis. According to X-ray data, REM iminodissucinates form well-defined crystals in two distinct isostructural groups.

Ionic Aggregation of Macromolecules as the Cause of the Kinetic (Non)Stability of Physicochemical Properties of Chitosan Solutions

Authors: Fomina V. I., Solonina N. А., Shipovskaya A. B.

Hydrodynamic, optical, colloid-flocculating, film-forming and structural morphological properties of diluted chitosan solutions (50–640 kDa) in acetate buffer (0.33 М СН3СООН + 0.2 М СН3СOONa), both initial ones and stored for ~1,850 days, were studied. It has been established that the decrease in the intrinsic viscosity of solutions over time is manifested for the reprecipitated and high-molecular-weight samples of chitosan to a greater degree. The viscosity drop effect is not affected by the use of untreated or sterile degassed distilled water to dissolve the polymer.

Exploration of Possibilities for Organic Selenides and Dihydroselenochromilium Salt Interaction with Diphenylpicrylhydrazyl

Authors: Pankratov A. N., Tsivileva O. M., Tsymbal O. A., Drevko Y. B., Tumskiy R. S., Marakaeva A. V.

Higher fungi – basidiomycetes play significant role as food and biological subjects for establishing the regularities of the living systems’ operation, development and response to the different-nature effectors impact. Insufficient activity of the living organisms’ antioxidant system interfering the ability of overcoming the negative consequences of oxidative stress (excessive level of free radicals in cells) is believed to be a reason for the organisms aging and death.

Synthesis and Ways of Formation of Hydroxyphenyl Substituted Triazolohexahydroquinazolines

Authors: Demidova D. M., Vasilkova N. O., Krivenko A. P.

With three-component condensation of 1,2,4-triazol-3-amine, hydroxy-substituted aromatic aldehyde (2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, 2-naphthalene-carbaldehyde), cyclohexanone, the aldehyde component has a defining impact on the shaping of triazologic hydroquinazolines with different types of rings articulation and the position of the double bond in them (C4a–C5 and C4a–C8a). When salicylic aldehyde is used, the positional isomers of the triazologic hexahydroquinazolines of angular and linear structure are formed in an equimolar ratio.

Interaction of Maleic Anhydride with 1,2-phenylenediamine under Different Conditions

Authors: Grinev V. S., Volkova A. V., Linkova E. I., Yegorova A. Y.

The reaction of maleic anhydride with 1,2-phenylenediamine when heated in an aprotic solvent, regardless of temperature, proceeds with the initial formation of the primary addition product, namely, 4-[(2-aminophenyl)amino)-4-oxobut-2-enoic acid, which further undergoes heterocyclization within two ways, due to the presence of several electrophilic centers in the molecule, depending on the reaction conditions.

Transport Properties of Membranes on the Basis of Tetradecylammonium Associates with Complex Compounds Silver(I)-сefotaxime

Authors: Kulapina E. G., Tyutlikova M. S., Mursalov R. K.

Transport properties of the plasticized polyvinylchloride membranes on the basis of tetradecylammonium associates with complex connections silver (I) – cefotaxime in the conditions of a diffusive mass transfer and a direct current are investigated. With variation of concentration of electrode active substances (0.5; 1; 2; 3%), the external solutions contacting with membranes (10-2–10-7 M). It is established that resistance of membranes depends on the content of electrode active substances (EAS) and concentration of perimembrane solutions of a cefotaxime.

Test-Determination of Amoxicillin in Medications

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

Amoxicillin is a semi-synthetic aminopenicillin β-lactam series with a wide spectrum of antibacterial activity against many gram-positive and gram-negative microorganisms. It is included in the list of essential drugs. Test systems for the detection and identification of amoxicillin are missing. We have obtained indicator papers with immobilized ninhydrin and p-dimethylaminobenzaldehyde for the test determination of amoxicillin. The reaction conditions were selected, depending on the temperature and time. Color scales for visual colorimetric and colorimetric determination were constructed.

Influence of Ascorbic Acid Isoforms on the Hydrodynamic Behavior of Chitosan Ascorbate Macromolecules in Aqueous Solution

Authors: Malinkina О. N., Gegel N. O., Shipovskaya A. B.

The hydrodynamic behavior of chitosan macromolecules in aqueous solutions of ascorbic acid (AscA) diastereomers was studied by means of capillary viscometry. A comparison of these systems with chitosan solutions in such traditional solvent media as hydrochloric and acetic acids, Na-acetate buffer was made. Concentration dependencies of the specific viscosity were plotted, and the intrinsic viscosity and the Huggins constant were evaluated.

Catalytic Conversion of Ethyl Alcohol on Zeolite Catalysts

Authors: Kuzmina R. I., Khoroshilov I. I., Chebotarev S. A.

This article describes the possibility of using bioethanol as a substitute for conventional fuel from petroleum feedstocks. Bioethanol obtained by fermentation from biomass is considered not only as an analogue of gasoline or a fuel additive, but also as a source of raw materials for the production of olefins, aromatic hydrocarbons and gasoline range hydrocarbons by means of catalytic conversion. At present, it is believed that the conversion of ethanol on zeolites proceeds in several stages.

Trifluoroacylation of Benzopirrolimidazolons under Various Conditions

Authors: Grinev V. S., Barabanov N. A., Linkova E. I., Yegorova A. Y.

The introduction of the (trifluoro)acetyl moiety into different heterocycles allows one to vary their physicochemical properties, change the nature and magnitude of biological activity, and also to carry out further chemical transformations. At the same time, modern methods of organic chemistry are aimed, inter alia, at increasing the efficiency of known and widely used chemical reactions and the possibility of directing along other paths when conducting syntheses under conditions, which are different from the classical ones.

Determination of Synthetic Food Dyes E110 and E124 in the Joint Presence by Vierordt’s Method and Derivative Spectrophotometry

Authors: Silaev D. V., Shestopalova N. B., Fomina Y. A., Rusanova T. Y.

The application of the Vierordt’s and the first derivative at the “zero crossing” methods was evaluated for the simultaneous determination of synthetic food dyes Yellow “sunset” (E110) and Ponso 4R (E124) in model solutions. The concentrations interval of components is established at which the principle of optical densities additivity is observed. For the implementation of the Vierordt’s method, wavelengths with the maximum difference in the absorption coefficients of the individual components (470.2 and 536.7 nm) were chosen.

On the Interaction of the Phosphoric Molybdenum Acid with the α-Amino Acids and Possible Applications of the Reaction Products in Ionometry

Authors: Chernova R. K., Varygina O. V., Zakharevich A. M.

The conditions of synthesis of ion associates of phosphorus-molybdenum ions with protonated form of lysine hydrochloride have been considered. It has been shown that the phosphoric molybdenum acid undergoes hydrolysis with the formation of the following products: НРО42– + Мо12О42– + 11Н2О. At pH 2 in aqueous solutions, the PhMA is stable, exists as anion [РМо12О42]3– and interacts with protonated form of lysine with the formation of associates 3[НLys]+[FMC]3–.

Data Approximation for Plotting the Binodal Curve on the Phase Diagrams of Some Ternary Salt – Water – Isopropyl (n-Propyl) Alcohol Systems

Authors: Cherkasov D. G., Il’in K. K.

A brief review of computational methods for the liquid-liquid equilibrium has been carried out, and their capabilities and limitations have been shown. Complications of such computational models for the liquid–liquid–solid equilibrium lead to a decreased accuracy of calculations. In this case, it is advisable for researchers to make use of the approximation of experimental data on the liquid – liquid and liquid – liquid – solid equilibria.

2-amino-3-formilchromen-4-one as “Connection-platform” in the Synthesis of Hybrid Systems under the Action of N-Nucleophiles

Authors: Ivanova A. L., Kanevskaya I. V., Ibragimova D. K., Fedotova О. V.

Показано, что 4H-хроменоны, функционализированные альдегидной группой в положении С3, способны образовывать гибридные системы, имеющие в своей структуре помимо хроменонового пиридиновый, пиримидиновый циклы. Кислая среда способствует раскрытию γ-лактонного фрагмента. Показана возможность дезактивации альдегидной группы с последующим деформилированием. 

The Effect of Surfactant Micelles on the Fluorescent Properties of a Complex of Yttrium with Levofloxacin

Authors: Danilina T. G., Smirnova T. D., Bryshkina A. D., Levina N. A., Nevryueva N. V.

The effect of complexation with yttrium ions and micellar media of surfactants on the fluorescent properties of levofloxacin was studied. The luminescence of levofloxacin depends on the acidity of the medium Т. Г. Данилина и др. Влияние мицелл поверхностно-активных веществ 378 Научный отдел Изв. Сарат. ун-та. Нов. сер. Сер. Химия. Биология. Экология. 2019. Т. 19, вып. 4 and is maximum in an acidic medium. It was shown that complexation with yttrium ions promotes the growth of the intrinsic fluorescence of levofloxacin by a factor of 2.

Extraction-Photometric Determination of Cobalt (II) with Hydroxytiophenols and Hydrophobic Amines

Authors: Zalov A. Z., Ibragimova S. A.

The possibility of using hydroxythiophenols (HTP) for the photometric determination of cobalt (II) has been studied. Aminophenols (AP) were used as hydrophobic amine: 2- (N,N-methylamino methyl)-phenol (AP1) and 2- (N, N-methylaminomethyl) -4-methylphenol (AP2). Dichloroethane, chloroform and carbon tetrachloride turned out to be the best extractants. With a single extraction with chloroform, 97.5–99.5% of cobalt is recovered as a complex. The cobalt (II) complex is extracted into chloroform in the pH range of 3.6–6.3.

Chemometric Algorithms for the Monitoring of Milk Quality by Potentiometric Titration

Authors: Monakhova Y. B., Kuznetsova I. V.

The acute problem in the analysis of dairy products is the potentiometric determination of the active and total titrated acidity of pasteurized milk from different manufacturers and their comparison with those for raw cow milk. In addition, for various expert purposes, fast definition of the manufacturer of this product is necessary. The conditions of potentiometric titration of pasteurized milk are specified. It is shown that the total acidity of pasteurized milk produced by different manufacturers differs insignificantly.

Comparison of Cytotoxic Activity of Compounds from the Benzimidazolequinazoline and Pyridopyrimidine Series

Authors: Ivonin M. A., Fomin A. S., Burygin G. L., Sorokin V. V.

Colorimetrically using the MTT assay the cytotoxic activity of 5-aryl-1,2,3,4,5,6-hexahydrobenz[4,5]imidazolo[1,2-a]quinazolines and a tautomeric mixture of 4-amino-2-phenyl-6H-pyrido[1,2-a] pyrimidin-3-carbonitrile with 2-(phenyl(pyridin-2-ylamino)methyl)- malononitrile was screened. These compounds were obtained by the three-component condensation of aromatic aldehydes (benzaldehyde, 3-bromobenzaldehyde, 4-methoxybenzaldehyde), heterocyclic amines (2-aminobenzimidazole or 2-aminopyridine) and cyclohexanone or malonic acid dinitrile in comparison with the starting amines.

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