Химия

. Electroanalytical properties of unmodified and modified by polyaniline and by CuO nanoparticles solid-contact potentiometric sensors which are based on associates of tetradecylammonium with complex compounds of silver (I) with cephuroxime, cephotaxime and cephazoline Ag(?-lac)2TDA in solutions of corresponding antibiotics were studied. It was revealed that Ag(?-lac)2TDA –based sensors had no specificity to the basic ion but showed sensitivity to other cephalosporins.

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.

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.

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 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.

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.

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.

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.

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».

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.