Химия

Ways of electrochemicals modification surface semiconducting electrode based on gallium arsenide (GaAs) was proposed in this work/ Behavior of unmodified and modified GaAs was investigated characterization was identified (steepness of electrode function, working interval? responses time, reproducibility). Possibility of using electrodes from GaAs for potentiometric titration of ions Cu2+ and Pb2+ was set. Modified GaAs-electrodes has improved electroanalitical characterizations in variants direct potentiometric titration was shown.

The examples of regiospecificity reactions of dienones derivatives of cyclohexane are made. On basis of 6-benzylidene -2-(5-nitrohetarilmetilidene) cyclohexanones were synthesized previously unknown dibromadducts, hexahydroindazoles and triazolochinazolines. The structure of derived compounds was ascertained by spectral methods. The probable reaction schemes are shown.

Catalytic reforming is the most used method for upgrading straight-run gasolines. The trends to modernize catalytic systems so that the reforming process can be used in the industrial setting are focused on the production of catalysts with a specifi c set of characteristics allowing to obtain a liquid commercial product with the required operational and ecological features, in addition to increase its yield at lower temperatures. This article investigates the effi ciency of the catalytic systems Pt/CVM, Pr/CVM as transformation processes of raw hydrocarbons.

In the course of this work, fl uorinated catalysts MoO3 /Al2 O3 -F for the olefi ns metathesis have been synthesized. The materials have been characterized by various physicochemical methods and tested in the propylene metathesis reaction. It has been shown that the support fl uorination leads to partial replacement of surface hydroxyl groups by F, which is accompanied by an increase in the strength of both Lewis acid sites and residual bridging OH groups. Increasing the fl uorine content on γ-Al2O3 up to 3 wt.

A comparative evaluation of the sorption capacity of synthetic and natural sorbents with respect to phenol and some of its derivatives has been carried out. Electrospun nanofi bers based on polyamide-6 (PA-6) were obtained under optimal conditions from a spinning solution of a polymer dissolved in a mixture of formic and acetic acids. The preparation of the clay mineral by the sieve method has been carried out, while the enriched fraction of glauconite (200–500 microns) has been isolated.

Currently iodine defi ciency diseases are one of the most important medical and social problems. In this regard, the purpose of the study is to determine the content of iodine, iodides, iodates in iodized salt, drinking and mineral water, seaweed, to determine the stability of the iodine content in salt. For the qualitative determination of iodides and iodates ions in salts and molecular iodine in seaweed, an iodine starch reaction has been carried out.

The chromatographic behavior of atorvastatin, rosuvastatin and simvastatin in the presence of the main modifi ers of the mobile phase: elution strength and buff er solution, has been studied by means of the reverse-phase high-performance liquid chromatography (HPLC) method. Optimal modifi cation conditions have been found and their application for the determination of statins under study in the pharmaceutical preparations Atorvastatin-OBL, Liprimar and Tulip has been shown. The Sr value is 0.03. The relative determination error does not exceed 7%.