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Background. The increasing pollution of natural waters by heavy metals has become a major problem in recent years, so their determination requires separation and pre-concentration techniques. Purpose. Development of a hybrid, sensitive sorption-spectrophotometric method for determining the Zn(II) ion using a polyethylene polyamine polyacrylonitrile (PPF-1) matrix immobilized in alizarin red C. Methodology. Research was carried out using a spectrophotometer, diffuse reflectance spectroscopy, IR spectroscopy and methods of mathematical statistics. Originality. For the first time, alizarin red C (AKS) was immobilized on a modified PPF-1 and a new matrix was used for the effective determination of Zn(II) Findings. The sensitivity of Zn(II) determination by selective immobilized ACS was maximum at 522 nm. The optimal pH for determining Zn(II) is 5.0 at room temperature. The linear range was found to be 6.5-40 mg/L, the detection limit was 0.6 mg/L, and the adsorption percentage was about 97%. [ABSTRACT FROM AUTHOR]

The article provides the results of the analysis of methods and instrument equipment for the assessment of quality parameters of retted flax straw and flax fiber. The traditional methods and equipment are presented. The devices developed for flax fiber quality testing used in the Russian Federation, the Republic of Belarus and Ukraine are described. Methods, equipment and modern technologies used to determine the quality of flax fiber in European countries, Canada and the United States are provided. The role of modern developments to improve the efficiency of flax production is noted. Promising methods and devices for determining the main quality indicators are identified. The use of the method of automated forecasting of technological value of fiber flax stalks makes it possible to conduct a comprehensive quality assessment based on morphological and anatomical analysis. Modern capabilities of electronic scanning microscopy provide the control of the chemical composition and structural elements of flax stems at various stages of growth and development, as well as during maceration. The use of infrared spectrometry provides high accuracy in determining humidity, strength, fiber content, and long fiber yield.However, along with high-precision equipment, there is the need for equipment and devices that allow determining the main technological indicators in the field with minimal labor, time and money costs. Research in this direction was previously carried out at the All-Russian Scientific Research Institute of Bast Crops Processing and in Kostroma State Technological University. However, the developments of the scientists were not tested in the production process and were not mass-produced. High speed and objective measurement methods will provide the accurate indicators during the process of maceration and primary processing of retted straw that will increase the technological value and competitiveness of flax fiber.

Introduction. The quality control of a medicinal product needs to be systematically improved in connection with a continuous increase in the requirements for the quality of medicines. When assessing the quality of substances and drugs, the most important indicators are authenticity, the content of the main substance and impurities. This makes it relevant to introduce modern physical and chemical methods of analysis into industrial practice in determining parameters such as authenticity, the content of the main substance and impurities. The choice and applicability of a particular method is possible only when conducting comparative studies on the application of a particular method to solve this problem. The method should preferably be recommended by the Pharmacopoeia, give unambiguous results, and the analysis should not be expensive and affordable. The methods chosen for comparative analysis are well known, but it should be noted that in recent years, instrument-making companies have significantly improved their instrument base and expanded their capabilities. Therefore, one of the objectives of this article is to demonstrate the capabilities of the selected methods for solving the problems of drug quality control using dalargin as an example.Aim. To develop methods for determining the authenticity of the active substance in a substance - Dalargin powder using NMR spectroscopy, IR spectrometry, and Mass spectroscopy. Conduct a comparative analysis of the applicability of the selected methods to solve the problem.Materials and methods. To determine the authenticity of the substance - the powder «Dalargin» used the methods of mass spectrometry, 13C NMR and 1H NMR spectrometry and IR spectrometry.Results and discussions. Methods have been developed for determining the authenticity of the test substance by NMR, IR, and mass spectrometry. A comparative study of the possibilities of the selected methods in solving the problem. Conclusions were drawn about the applicability of the NMR method not only in determining the authenticity of dalargin, but also in solving the problem of determining the content of the main substance and impurities.Conclusion. Authenticity methods have been developed in the substance - Dalargin powder by Mass, IR, and NMR spectrometry. It has been established that 1H NMR spectrometry is a more informative method for authenticating.

The paper analyzes the structure of Upper Devonian reef strata within Moroshkinsky, Ust-Tsilemsky and Severo-Tebuksky reference sites located in the territory of the Komi Republic and Nenets Autonomous Okrug. Based on the re-interpretation of the materials of geophysical well logging involving lithologic description of core and results of its laboratory studies, a detailed analysis of the structure of Domanic-Famenian part of the profile has been made, and a correlation pattern for deep well profiles has been drawn. As a result of well log correlation, some of the stratigraphic boundaries have been updated, the scope of lithologic and stratigraphic subdivisions has been determined, reference bands with good visibility on geophysical diagrams and easily traceable carbonate formations known to geologists as F1, F2, F3, F4, F5, as well as inter-formation bands, have been specified. The paper contains the results of a geochemical study of the Upper Devonian reef deposits of the wells drilled in the territory of Moroshkinsky, Ust-Tsilemsky and Severo-Tebuksky sites. It presents content distribution of organic carbon, chloroform and alcohol-benzol extracted bitumoids in the rocks of certain well horizons, and describes oil generation potential of the rocks on the basis of pyrolytic data. Based on the comprehensive analysis of the results of laboratory core analysis and materials of production log tests, reservoir quality discrimination has been performed, an evaluation of their quantitative parameters and fluid content has been made. Porosity factor has been selected as the criterion for evaluation of reservoir properties of the rocks. Determination of porosity by neutron gamma-ray logging has been performed following the method of two guide formations using the dependencies developed by JSC KamNIIKIGS. For evaluation of quantitative parameters of carbonate reservoirs, the results of standard core analysis were used: effective porosity, absolute permeability to gas, and volumetric density. The results of the research can be used during prospecting and exploration in the territory of the three reference sites of interest.

In this study, the author set out to determine the chemical composition and possible use of a substance, which remnants were found on a tile fragment made of soft brown shist. This item was discovered in the occupa-tion layer of a Neolithic settlement belonging to the Boborykino culture (Mergen 3), located on the terrace of Lake Mergen in the forest-steppe of the Ishim area (south of Western Siberia). By analogy with the complexes of the Boborykino culture in the Tobol area — Yurtobor 3 (7701 ± 120 BP (UPI 559)) and Tashkovo 1 (7440 ± 60 BP (LE 1534)) — which age was determined using carbon-14 dating, the Mergen 3 settlement can be attributed to the second half of the 7th millennium Cal. BC. The fragment measuring 3.0 × 2.1 × 0.55 cm has a spherical indenta-tion in the centre measuring 2.0×2.0×0.2 cm with a volume of 0.118 cm3 (0.118 ml). The whole item probably had a square shape with rounded and slightly raised edges. A visual analysis of the spot was carried out using an MBS-10 binocular microscope at a magnification of 16×. The analysis revealed a brown substance on the edges of the indentation, which looked like a dark porous carbon-like spot in the centre. These remnants were studied using a Bruker ALPHA FT-IR spectrometer with an Eco-ATR module — a single reflection ATR sampling module equipped with a zinc selenide crystal (ZnSe) that allows you to analyse liquid, solid and powder samples without preliminary sample preparation. The measurements were performed in the wavenumber range of 300–4000 cm-1 at a resolution of 4 cm-1. Some of the most significant absorption bands (709; 975; 1,024; 1,027 cm-1) were ob-served, which characterise vibrations bending and stretching the bonds in the skeleton of an organic molecule containing single С–С and С–О bonds. The obtained spectra are most consistent with the IR absorption spectra of resin acids, in particular, dehydroabietic acid that is present in resin obtained from coniferous trees. Consider-ing the small volume of the above-mentioned substance and the limited of its burning, the author excludes the use of this tile as a lamp, the use of the substance for the preparation of glue that held together the parts of complex tools, as well as the use of the substance for healing wounds and for cosmetic purposes, which involved addi-tional ingredients. Signs of burning indicate the use of the artefact for rituals, in particular for obtaining finely dis-persed soot employed when applying tattoos. The conducted experiment showed that the soot from a burnt drop of fresh resin covered 4 cm2 of the wrist area. Soot formed at the very beginning of the combustion process (probably combustion of volatile components), then the substance was oxidised without noticeable emissions. The remnants of the porous substance on the tile confirm the importance of the moment of resin burning with the abundant production of soot. However, the possibility that there were other unknown areas of application of gali-pot obtained from coniferous trees is not excluded. In any case, it is safe to say that the early Neolithic population living in the Ishim area purposefully used natural resins in their activities.

The article presents a review of studies carried out mainly by the researchers of the Ufa State Petroleum Technological University, which are aimed at detection of new properties of carbon in such condensed media as petroleum and coal pitches, steels and cast irons. Carbon plays an important role in the industry of construction materials being a component of road and roof bitumen and setting the main mechanical properties of steels. It was determined that crystal-like structures appear in classical glass-like substances – pitches which contain several thousands of individual hydrocarbons of various compositions. That significantly extends the concept of crystallinity. In structures of pitches, the control parameter of the staged structuring process is paramagnetism of condensed aromatic hydrocarbons. Fullerenes were detected in steels and cast irons and identified by various methods of spectrometry and microscopy. Fullerene С60, which contains 60 carbon atoms, has diameter of 0,7 nm and is referred to the nanoscale objects, which have a significant influence on the formation of steel and cast iron properties. It was shown that fullerenes appear at all stages of manufacture of cast irons; they are formed during introduction of carbon from the outside, during crystallization of metal in welded joints. Creation of modified fullerene layers in steels makes it possible to improve anticorrosion and tribological properties of structural materials. At the same time, outside diffusion of carbon from the carbon deposits on the metal surface also leads to formation of additional amount of fullerenes. This creates conditions for occurrence of local microdistortions of the structure, which lead to occurrence of cracks. Distribution of fullerenes in iron matrix is difficult to study as the method is labor-intensive, it requires dissolution of the matrix in the hydrofluoric acid and stage fullerene separation with further identification by spectral methods.

Steels of various purposes are used in the construction industry, for example, as the reinforcement material in reinforced concrete structures. In the oil and gas industry, steel structures are used for storage and transportation of explosive toxic media. In this case the catastrophic damages might take place, that points at insufficiently deep knowledge about the processes running in structural materials when load is applied. Recent studies show that many properties of steel are set at the nanoscale level during crystallization from the molten metal and thermal treatment. To detect and identify fullerenes С60 and С70, which are independent nanoscale objects in steel structure, by various methods requires studying of how these objects influence on formation of steel properties. Iron atoms can serve as a catalyst and, interacting with large aromatic structures or fragments of the graphite planes, they form voluminous fullerene-type structures. The inverse phenomenon, i.e. influence of the formed nanoscale objects on structuring of the iron atoms, is also possible, as fullerene size is comparable with the size of the stable nucleus of the iron crystalline phase. The article discusses the issue of mechanisms of fullerenes formation in steels and cast irons. The most complicated issue in the study is the fullerenes identification by spectral methods as the quantity of released molecules is small. In order to increase the sensitivity of the fullerenes IR-spectrometry method, potassium bromide has been proposed to use. Dried and reduced sediment obtained as a result of dissolving iron matrix in steels is mixed with potassium bromide, the mixture becomes bright-orange. This fact points to presence of bromic fullerenes and to presence of fullerenes in the studied specimens. It is shown that the offered specimen preparation algorithm significantly increases sensitivity of the method.

Aim. To analyze the carbonyl derivatives of 7-((3-thio-4-R-4H-1,2,4-triazole-5-yl)methyl)theophylline their mother substance was synthesized and its interaction with α-haloketones series was carried out. Methods and results. The physical-chemical properties of the obtained compounds have been studied and their structures have been confirmed by elemental analysis, infrared spectrometry, 1H NMR spectrometry, UV spectrophotometry and gas chromatography mass spectrometry. Preliminary computer study of acute toxicity and biological activity has been also carried out. It has been determined that the obtained compounds may exhibit diuretic and analeptic activity and 1,2,4-triazole fragment can theoretically increase it. Conclusion. Preliminary prediction of acute toxicity has showed that the compounds are low-toxic.

The adverse effects of microplastics (MP) found in food on the health have recently been recognized as a new source of human health risks. In order to evaluate and minimize them, it is necessary to evaluate the exposure using sensitive and specific methods. The aim of the research was the substantiation of methodological approaches to the identification and quantification of microplastics in food based on the analysis of literature data. Material and methods . Literature selection was carried out using the PubMed international reference database for the period from 2014 to 2023 using keywords corresponding to the context of the research theme. A total of 159 sources were selected, of which 94 original and review papers were included in the review according to the criteria of their relevance to the problem under consideration, scientific reliability and completeness. Results . At present, various approaches have been developed that make it possible to isolate MPs from complex bioorganic matrices (such as, for example, seafood), classify them by chemical composition, and quantify their content through the mass or number of particles. Among the most developed physic-chemical methods for the analysis of MPs are Fourier transform IR spectrometry and Raman microspectrometry, pyrolysis gas chromatography - mass spectrometry, thermogravimetric analysis, as well as approaches based on liquid chromatography, microfluorimetry, analytical scanning and transmission electron microscopy and others. Unsolved problems in the field of MP research in food include the high laboriousness and low performance of the identification technologies used, the lack of reference and standard samples of MP, the complexity of the equipment used, which makes it difficult to use it for routine hygienic control. The issue of the influence of MP aging degree on the results of its qualitative and quantitative determination has not been sufficiently studied. Some hopes in the field of development of rapid analysis of MTs are pinned on the use of aptamers. Conclusion . Existing analytical methods make it possible to determine the content of MPs in environmental objects, but further improvement and validation of these methods is required in relation to the assessment of the content of MPs in various types of food., Competing Interests: The author declares no conflicts of interest., (Copyright© GEOTAR-Media Publishing Group.)