Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


Химия

Phase Diagram of the Potassium Thiocyanate – Water Binary System

The phase diagram of the potassium thiocyanate–water binary system was studied by the visual polythermal method and by the method of time–temperature curves over а temperature range – 35–180 оС. There is an eutectic equilibrium at –32.6 оС in the system; the solid phases of this equilibrium are ice and individual potassium thiocyanate. The composition of the liquid phase of the eutectic state was determined.

Processing of Reaction Masses of Lewisite in Arsenic-сontain Commercial Products

The article presents the results of the development of technical decisions of processing of products detoxification lewisite in the arsenic oxide (III). Shows a general scheme and the basic process steps of this process. Particular attention is paid to the method of removal of arsenic (V) from the system, which can contaminate the final product. 

Sorbents Based on Natural Bentonites Modified with Iron (III) and Aluminum Polyhydroxocations by the Sol-Gel Method

Natural bentonite was modified with iron (III) and aluminum polyhy- droxocations by the sol–gel technique. This modification of natural bentonite has been found to cause changes in its chemical composi- tion, structural and sorption properties. The modified sorbents are fine-porous (nanostructured) objects with the predominance of 1.5–6.0 nm pore size. The specific surface area of our sorbents depends on the method of modification and the amount of the modifying component introduced (iron (III) or aluminum).

To the Question the Choice of a Derivatizing Agent for the Transfer of Methylphosphonic Acid and its O-alkils Ethers to Chromatographic Derivatives

The products of the derivatization of methylphosphonic acid and its ethers were investigated by gas chromatography – mass spectrometry. The optimum conditions of the derivatization of higher-boiling organo- phosphorus compounds were described.

Effect of Temperature, Isotopic Composition of Water and Ethanol on the Tautomeric Equilibrium of Sulphonated Phenylazonaphtholes

The effect of temperature, isotopic composition of water and ethanol on the tautomeric equilib- rium of two phenylazonaphtholes that differ by sulphonic group in benzene ring was investigated spectrophotometrically. It was established that enhancement of water structure under decrease of temperature or change of common water to heavy one shifts the azoquinonhydrazone tautomeric equilibrium to more polar hydrazone tautomer.

Fragmentation Canals of Molecular Ions of GC-MS-Registered Components of Media of Shiitake Basidiomycete Submerged Cultivation in the Presence of Diacetophenonylselenide. Isomerization of Dihydrofurans and Their Cation Radicals

The molecular ions fragmentation canals of substances registered by means of the GC-MS method in the media of Lentinula edodes (shiitake) basidiomycete submerged cultivation in the presence of diacetophenonylselenide have been substantiated. At the B3LYP/6-311++G(3df,3pd) and UB3LYP/6-311++G(3df,3pd) level, involving the NBO analysis and the R. F. W. Bader’s «Atoms in Molecules» quantum theory (QTAIM), isomeric transformations of dihydrofurans have been considered.

The Peculiarities of Synthesis of Acid Esters of Methylphosphonic Acid

The peculiarities of synthesis of acid esters of methylphosphonic acid for further use in the system of chemical and analytical control of the environment have been discovered.

Synthesis of Monodisperse Magnetite: The Effect of Temperature, Sodium Hydroxide and Citric Acid Concentrations on the Size of Nanoparticles

The effect of temperature, sodium hydroxide and citric acid concentrations on the size of magnetic magnetite nanoparticles was studied. Optimal conditions for synthesis of magnetite stabilized by citric acid with narrow size distribution were found. The average size of the nanoparticles determined by dynamic light scattering and transmission electron microscopy 12 ± 3 and 6 ± 2 nm, respectively was established. The chemical composition and structure of magnetite nanoparticles was confirmed by X-ray diffraction method.

Mass Fraction Evaluation of the Basic Substance in Dialkyl Methylphosphonate Samples by Potentiometric Titration

A technique for the mass fraction evaluation of the basic substance in dialkyl methylphosphonate samples by automatic potentiometric titration is presented. A comparison was made with a certified technique of visual titration. Several advantages of our method are shown: the ability to automate analysis, a reduced sample weight, a constant and precise volume of a titrant drop, a reduced detection time, avoiding the use of chemical indicators, an improved precision of analysis.

Determination of the Contents of Arsenic, Mercury, Copper, Nickel and Zinc in the Soil and Ventilating Emissions by Method of Atomic Absorption Spectrometry (AAS)

The method of atomic absorbing spectrometry (AAS) determined the content of mobile forms of copper, nickel and zinc, and total content of mercury and arsenic in the soil samples selected in a residential zone Samara, and copper in the ventilating emissions. For soils the sample preparation stage contribution to the general error of analytical definition is estimated. For ensuring correctness definition of the content of copper in the ventilating emissions the correction coefficient cons idering existence of a systematic mistake is calculated.

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