Research of the Composition of Wax Deposits and the Processes of Their Formation in Transformer Oil doi.org/10.22184/2227-572X.2023.13.5.348.358
This paper presents the results of studying the elemental composition of sediments, including waxy ones, from high-voltage oil-filled equipment in which transformer oil has been in use for more than 30 years. Using the method of inductively coupled plasma mass spectrometry, metals such as Cu, Fe, Zn, Ni, Cd, Co, Pb, Cr, and Mn were detected in deposits from transformers and high-voltage bushings. At the same time, the deposits from power transformers contain the greatest amount of iron (Fe) >> copper (Cu) > zinc (Zn), and the deposits from high-voltage oil-filled bushings contain copper (Cu) ≈ iron (Fe) >> zinc (Zn). Special experiments have been carried out to confirm the mechanism of formation of organometallic compounds in oil, in particular, the formation of stearic acid salts. The experiments consisted of preparing model solutions close to the composition of transformer oil and consisting of hexane, ionol, butyl stearate and stearic acid; adding to them powdered metals (Cu, Sn, Zn, Fe, Al) and their oxides (CuO, SnO, ZnO, Fe2O3, Al2O3); keeping the mixture for 1–20 hours and then determining the concentration of the components. Research has shown that salts of carboxylic acids in an organic matrix are formed by the interaction of carboxylic acid with metals (Zn, Fe, Al) or their oxide films (ZnO, Fe2O3, Al2O3). With less active metals (Cu and Sn), as well as with their oxides (CuO and SnO), the consumption of stearic acid was not observed, that is, the reaction between the acid and additives (Cu, Sn, CuO, SnO) does not occur, this indicates that that copper and tin in oil deposits are associated with other anions, mainly with the sulfide ion.
Map of Analytics 2022: Miniaturized Instruments, COVID 19, Microplastics, Deep Eutectics doi.org/10.22184/2227-572X.2023.13.5.360.365
This publication is the sixth in a series of articles containing the results of regular monitoring with respect to fronts of analytical chemistry development. Fronts are traditionally related to groups of highly cited core publications, often cited (co-cited) together. In 2022, as in previous years, intensive research related to the medicalization and miniaturization of chemical analysis (sensor and microfluidic devices) continued. Many works are aimed at the detection of pathogens, including COVID 19 virus. The determination of microplastics and extraction by deep eutectic solvents belong to ecologically significant areas of research. The use of ion mobility spectrometry complements the widespread use of chromatography mass spectrometry.
Current Trends in the Application and Analytical Control of Niobium and Tantalum. Short Review doi.org/10.22184/2227-572X.2023.13.5.366.378
Modern industry is associated not only with the use of new promising materials and technologies, but also with the development of traditional ones, the effectiveness of which has been confirmed by significant production experience. The cornerstone of most technologies is the reliability of the analytical control results of an industrial process. The work examines domestic and foreign requirements for one of the most popular types of rare refractory metals: niobium and tantalum, as well as materials based on them. A standardized regulatory framework for analytical control methods is shown. Summarizes information about modern analytical methods published in periodical scientific and technical literature. Brief descriptions of the methods and their characteristics are given. An analysis of methods for monitoring niobium and tantalum and materials based on them revealed the most common methods (ICP-AES, ICP-MS) and their inherent advantages and limitations. Solid-phase analysis methods, namely X-ray fluorescence, are very profitable and promising. Simultaneous determination of all elements, a wide range of concentrations from 10–4 to 100%, the absence of lengthy and labor-intensive sample preparation, rapid analysis, the non-destructive nature of the method, the absence of the need to use adequate standard samples in the case of using the fundamental parameters method (FPM) – all this is undeniable XRF has the advantage of characterizing niobium and tantalum, as well as most other refractory materials.
Prevention and Treatment of Cardiovascular Diseases with Natural Antioxidants doi.org/10.22184/2227-572X.2023.13.5.338.344
Numerous epidemiological, clinical and therapeutic studies have shown that natural antioxidants can be effectively used for the prevention and treatment of cardiovascular diseases, both in their pure form and as part of food products. Information on the use of antioxidants is provided in this brief review. As evidence, an extensive, well-chosen bibliography (more than 100 references) is provided. Each statement is supported by relevant scientific research.
Chemical-analytical Center Arbitrage. From the Moment of Creation to the Present Time doi.org/10.22184/2227-572X.2023.13.5.320.327
The Chemical Analytical Center Arbitrage (hereinafter referred to as ChAC Arbitrage) is a multi-profile analytical laboratory that has been operating for more than 20 years on the basis of FGUP D. I. Mendeleev institute for metrology (VNIIM). The main are activities related to analytical support of research in the field of monitoring and environmental protection, food safety and raw materials; production testing (including for certification purposes), certification of toxic waste, development of measurement methods, development of national and international standards, expert and arbitration researches. The accreditation field of the ChAC Arbitrage includes more than 100 measurement methods, suitable, among other things, for measurements and control in the field of state regulation. ChAC Arbitrage is the single center in the Russian Federation accredited for the research of unknown composition samples. The personnel of the ChAC Arbitrage are specialists with qualification in chemistry, physics, ecology, and metrology. The Center is equipped with modern analytical equipment for conducting research in the field of organic and inorganic chemistry (gas and liquid chromatography and chromatography-mass spectrometry, thermo gravimetric analysis, ion chromatography and capillary electrophoresis, atomic emission spectrometry, mass spectrometry with ISP, spectrophotometry, fluorimetry, etc.).
Preparing for Accreditation Together With LIMS doi.org/10.22184/2227-572X.2023.13.5.380.388
In Russia, laboratory information management systems (LIMS) have been used in laboratories in various industries for more than 20 years. LIMS software is not only a means of automating laboratory activities, but also an important tool for managing its data. Having a LIMS helps the laboratory cope with a large number of documents and simplifies preparation for accreditation. The fundamental regulatory document in the laboratory today is GOST 17025-2019. General requirements for the competence of testing and calibration laboratories. GOST specifies the requirements for managing data and information contained in computerized systems (including LIMS). But there are no clear instructions on how laboratories should document/prepare for accreditation, if it has a functioning LIMS. The article discusses the requirements of GOST 17025, including the requirements for LIMS validation, as well as documentary evidence of the presence and use of LIMS in the laboratory.