rus
Exhibitions and Conferences
Analytics of Substances and Materials
M. N. Lyutikova, A. V. Ridel, S. I. Sotnikov
Investigation of Gas Formation in Dielectric Liquids https://doi.org/10.22184/2227-572X.2023.13.3.198.204
Monitoring the formation of gases in liquid dielectrics during their operation in high-voltage transformers is of great practical importance in diagnosing the condition of the internal insulation of oil-filled equipment. The composition of the gas mixture and the dynamics of the growth of concentrations of certain gases can provide valuable information about the appearance and possible nature of a defect inside the equipment. The available methods for determining gases are designed to monitor the condition of electrical equipment filled with petroleum-based transformer oil. Meanwhile, the global power industry is gradually moving to alternative fluids such as natural and synthetic esters, as well as mixtures of these esters with transformer oil. Ester dielectric fluids are highly biodegradable, fire retardant, highly water soluble without compromising electrical insulating properties, and are environmentally friendly and renewable. Accordingly, their use in high-voltage equipment requires the development of control methods. The paper presents the results of a study of the formation of gases under the influence of discharge processes in a synthetic ester liquid, as well as mixtures of transformer oil with an ether content of 5% to 30% by volume. The determination of gases dissolved in liquids was carried out on a gas chromatograph according to a new method.
Investigation of Gas Formation in Dielectric Liquids https://doi.org/10.22184/2227-572X.2023.13.3.198.204
Monitoring the formation of gases in liquid dielectrics during their operation in high-voltage transformers is of great practical importance in diagnosing the condition of the internal insulation of oil-filled equipment. The composition of the gas mixture and the dynamics of the growth of concentrations of certain gases can provide valuable information about the appearance and possible nature of a defect inside the equipment. The available methods for determining gases are designed to monitor the condition of electrical equipment filled with petroleum-based transformer oil. Meanwhile, the global power industry is gradually moving to alternative fluids such as natural and synthetic esters, as well as mixtures of these esters with transformer oil. Ester dielectric fluids are highly biodegradable, fire retardant, highly water soluble without compromising electrical insulating properties, and are environmentally friendly and renewable. Accordingly, their use in high-voltage equipment requires the development of control methods. The paper presents the results of a study of the formation of gases under the influence of discharge processes in a synthetic ester liquid, as well as mixtures of transformer oil with an ether content of 5% to 30% by volume. The determination of gases dissolved in liquids was carried out on a gas chromatograph according to a new method.
Tags: essential oil mixtures ester dielectric liquid formation of combustible gases gas chromatography insulating mineral oil sum of hydrocarbon gases газовая хроматография изоляционное минеральное масло сложноэфирная диэлектрическая жидкость
A. G. Chernobrovina, N. E. Kulikova, N. N. Roeva, O. Yu. Popova
Optimization of Sucrose Inversion Conditions and Evaluation of the Accelerated Ferricyanide Method for Determining Total Sugar https://doi.org/10.22184/2227-572X.2023.13.3.206.214
The sugar content in raw materials and food products largely determines their usefulness and quality. Therefore, much attention is paid to methods of controlling the content of this important ingredient. An express method for determining total sugar is proposed: the method of sucrose hydrolysis is selected, the conditions (optimal temperature, time, volume of hydrochloric acid) of complete sucrose hydrolysis without decomposition of reaction products, as well as without hydrolysis of lactose, maltose and dextrose are specified. Two methods with different hydrolysis conditions were compared: the standard method (Bertrand) according to GOST 5903-89 (sucrose hydrolysis was carried out at a temperature of 67 °C) and the accelerated ferricyanide method, including sucrose hydrolysis at a temperature of 100 °C.
Reliable data were obtained with a significant (5 times) reduction in the time of sucrose hydrolysis, and, consequently, the duration of the entire analysis compared to the standard method for determining sugar. The accelerated method for determining reducing substances (PB) and the total sugar content in bakery and confectionery products can be considered a priority among chemical research methods. This technique can be recommended for operational analytical control.
Optimization of Sucrose Inversion Conditions and Evaluation of the Accelerated Ferricyanide Method for Determining Total Sugar https://doi.org/10.22184/2227-572X.2023.13.3.206.214
The sugar content in raw materials and food products largely determines their usefulness and quality. Therefore, much attention is paid to methods of controlling the content of this important ingredient. An express method for determining total sugar is proposed: the method of sucrose hydrolysis is selected, the conditions (optimal temperature, time, volume of hydrochloric acid) of complete sucrose hydrolysis without decomposition of reaction products, as well as without hydrolysis of lactose, maltose and dextrose are specified. Two methods with different hydrolysis conditions were compared: the standard method (Bertrand) according to GOST 5903-89 (sucrose hydrolysis was carried out at a temperature of 67 °C) and the accelerated ferricyanide method, including sucrose hydrolysis at a temperature of 100 °C.
Reliable data were obtained with a significant (5 times) reduction in the time of sucrose hydrolysis, and, consequently, the duration of the entire analysis compared to the standard method for determining sugar. The accelerated method for determining reducing substances (PB) and the total sugar content in bakery and confectionery products can be considered a priority among chemical research methods. This technique can be recommended for operational analytical control.
I. A. Filenko
Determination of T 2 Toxin by Gas Chromatography after Derivatization with Trifluoroacetic Anhydride https://doi.org/10.22184/2227-572X.2023.13.3.216.219
The content of mycotoxins in food products of grain nature is one of the indicators of its safety. The article describes the determination of T 2 toxin in modern laboratory with domestic equipment. A calculation formula is proposed that does not require comparison of peak areas. A wider range of detectable concentrations of T 2 toxin has been established. Statistical processing of the results was carried out and metrological characteristics were calculated.
Determination of T 2 Toxin by Gas Chromatography after Derivatization with Trifluoroacetic Anhydride https://doi.org/10.22184/2227-572X.2023.13.3.216.219
The content of mycotoxins in food products of grain nature is one of the indicators of its safety. The article describes the determination of T 2 toxin in modern laboratory with domestic equipment. A calculation formula is proposed that does not require comparison of peak areas. A wider range of detectable concentrations of T 2 toxin has been established. Statistical processing of the results was carried out and metrological characteristics were calculated.
Tags: derivatization ecd-detector gas chromatography t 2 toxin газовая хроматография дериватизация т 2 токсин эзд-детектор
Chemical Analysis Metrology
R. A. Belousov, A. A. Nazarova, O. M. Rosenthal
Assessment of the Quality of Hydrochemical Information, Taking into Account Metrological Requirements https://doi.org/10.22184/2227-572X.2023.13.3.220.225
The influence of measurement accuracy on the correctness of conclusions about the compliance of water quality with the established requirements is analyzed. It is shown that the error rates are 30% on average for common pollutants characteristic of drinking water and 40% for substances characteristic of natural waters. At the same time, the risk of false conclusions about the compliance / non-compliance of water with metrological requirements reaches 20–50% in the range from 0.9–1.2 MPC to 0.6–3.3 MPC at measurement error standards typical for common pollutants. The conclusion is made about the need for an optimal choice of methods and means for measuring hazardous substances, which guarantees an acceptable risk of false conclusions.
Assessment of the Quality of Hydrochemical Information, Taking into Account Metrological Requirements https://doi.org/10.22184/2227-572X.2023.13.3.220.225
The influence of measurement accuracy on the correctness of conclusions about the compliance of water quality with the established requirements is analyzed. It is shown that the error rates are 30% on average for common pollutants characteristic of drinking water and 40% for substances characteristic of natural waters. At the same time, the risk of false conclusions about the compliance / non-compliance of water with metrological requirements reaches 20–50% in the range from 0.9–1.2 MPC to 0.6–3.3 MPC at measurement error standards typical for common pollutants. The conclusion is made about the need for an optimal choice of methods and means for measuring hazardous substances, which guarantees an acceptable risk of false conclusions.
Tags: assigned error characteristic conformity/non-compliance conclusion error rate measurement error water quality indicator заключение о соответствии/несоответствии норма погрешности погрешность измерений показатель качества вод приписанная характеристика погрешности
Analytical Methods and Instruments
O. V. Monogarova
Methods of Qualitative Express Analysis of Medicines: Present and Future 10.22184/2227-572X.2023.13.3.190.197
The article is a brief overview of the methods used in pharmacy for qualitative rapid analy-sis of medicines. Methods of identification of active substances in pharmacy conditions are systematized. The analytical capabilities of the methods are compared, their advantages and limitations are indicated. The main prospects for the development of test-methods for the control of the authenticity of medicines are noted. Particular attention is paid to various options for colorimetry, which in the future may become one of the main methods for quickly controlling the authenticity of drugs and monitoring their quality.
Methods of Qualitative Express Analysis of Medicines: Present and Future 10.22184/2227-572X.2023.13.3.190.197
The article is a brief overview of the methods used in pharmacy for qualitative rapid analy-sis of medicines. Methods of identification of active substances in pharmacy conditions are systematized. The analytical capabilities of the methods are compared, their advantages and limitations are indicated. The main prospects for the development of test-methods for the control of the authenticity of medicines are noted. Particular attention is paid to various options for colorimetry, which in the future may become one of the main methods for quickly controlling the authenticity of drugs and monitoring their quality.
Tags: authenticity control drug express analysis pharmacy test methods контроль подлинности лекарственное средство тест-методы фармация экспресс-анализ
Historic chapters
V. F. Selemenev, O. B. Rudakov
Voronezh Scientific Schools on Chromatographic and Other Related Methods https://doi.org/10.22184/2227-572X.2023.13.3.226.230
The article considers the stages of formation of scientific and pedagogical schools of chemists in higher educational institutions of Voronezh, engaged in the training of scientific personnel, the development of chromatography, ion exchange, sorption and membrane separation and concentration processes. Some results of scientific activity of Voronezh chemists are given.
Voronezh Scientific Schools on Chromatographic and Other Related Methods https://doi.org/10.22184/2227-572X.2023.13.3.226.230
The article considers the stages of formation of scientific and pedagogical schools of chemists in higher educational institutions of Voronezh, engaged in the training of scientific personnel, the development of chromatography, ion exchange, sorption and membrane separation and concentration processes. Some results of scientific activity of Voronezh chemists are given.