Cancer is the leading cause of death in the world. The development of oncopathology is closely related to various changes in the genetic material that occur in malignantly transformed cells. Medical decision-making requires a clear differentiation between normal and pathological indicators, which are, among other things, the results of application of quantitative methods in laboratory medicine. Studies of DNA isolated from a patient’s biological material, identification and measurement of the content of nucleotide sequences acting as oncopathology biomarkers allow to solve the problems of determining the genetic prerequisites for cancer, its early diagnosis, determining the treatment strategy, monitoring, and confirming the patient’s cure.

The purpose of this research is to develop the main approaches to the design of DNA reference materials (RMs) for metrological support of molecular diagnostics of oncopathology through the example of the RM for the HER2 gene sequence content in the human genome, with the value of «the number of copies of the DNA sequence» which is metrologically traceable to the natural SI unit «one».

In the course of the research, a technique for measuring the HER2 gene amplification (the number of copies of the gene sequence per genome) was developed based on the use of the digital PCR method (dPCR). Comparability of measurement results for the method developed by the authors, and the results obtained using a commercial kit by the MLPA method on samples of human biological material is shown.

Five permanent cell lines obtained from the CUC «Vertebrate Cell Culture Collection» were characterized in relation to the copy number ratios of HER2 gene sequence and CEP17 and RPPH1 genes sequences. A cell line with the HER2 gene amplification was identified. The results obtained will be used to create the RM for the copy number ratio of the HER2 gene sequences and the RPPH1 and CEP17 gene sequences. Creation of matrix DNA RMs based on human cell cultures certified using dPCR will allow transferring the unit of copy numbers of the DNA sequence to calibrators included in medical devices, thereby ensuring the required reliability and comparability of measurement results in the laboratory diagnostics of oncopathology, as well as the possibility of calibrating routine methods of DNA diagnostics and intralaboratory quality control.

To date, antibiotics are often used in the treatment of infectious diseases in medicine and veterinary medicine, as well as growth promoters in animal husbandry. The uncontrolled use of antibiotics leads to antibiotic residues in food products that are easily transmitted to humans through food chains. Due to these undesirable effects, as well as in connection with the circulation of substandard and counterfeit medicinal products, it is necessary to control the quality of medicinal products, as well as monitor the food safety of animal products by determining the content of drug residues using reference materials (RMs).

The aim of this research was to develop a CRM for the composition of tylosin tartrate.

In the course of the research, a method for preparing the initial RM was tested and successfully implemented, a critical analysis of methods for measuring the content of tylosin tartrate was carried out, and the choice of the HPLC method as the main method for quantitative determination of the certified value of the measured quantity (mass fraction of tylosin) was justified. The disadvantages of the microbiological method and the titrimetry method as alternative methods were shown. In accordance with RMG 93–2015 and GOST ISO Guide 35–2015, the standard uncertainty of the RM certified value from the characterization method, heterogeneity and instability of the material was estimated. The expanded uncertainty of the certified value was calculated. The result of the work performed was the approval of a new type of the CRM for the composition of tylosin tartrate GSO 11632 2020.

Normalized metrological characteristics: the mass fraction of tylosin is 800–1100 µg/mg, the relative expanded uncertainty at k = 2, P= 0.95 is 6%. The CRM is stored in sealed ampoules separately from food and feed in a dry and dark place at a temperature from plus 4 °C to minus 18 °C, the shelf life of the CRM is 4 years.

The practical significance of the results obtained makes it possible to expand the possibility of certification of measurement methods and control of the accuracy of the measurement results of the mass fraction of tylosin in veterinary medicinal products, food and food raw materials, animal feed, and environmental objects. The CRM can also be used to identify tylosin in medicinal products and to determine the susceptibility of pathogens to tylosin.

The requirements for thermal analysis instruments are increasing in terms of their metrological support with the development of scientific and technological progress in the field of metrological supervision and electronics industry. The study of determining the phase transition temperature, namely the Curie temperature, is of particular relevance for the metrological support of the applied thermal analysis instruments and traceability to the basic physical units.

The purpose of the research was to test the possibility of using materials based on alumel, nickel and iron silicide (trafoperm) as phase transition temperature standards for candidate reference materials of phase transition temperatures (RMs) traceable to the SI unit of the «temperature» value.

The procedure for measuring the phase transition temperatures (Curie temperature – T_C) was carried out by the thermomagnetometric method using an STA 449 F5 JUPITER thermal analyzer from the State Primary Standard GET 173-2017. The determination of the RM certified value was carried out in accordance with GOST ISO Guide 35–2015, the contributions to the uncertainty from the heterogeneity of the initial materials were evaluated, and the short-term and long-term stability of the materials were studied.

A comparison of the certified values of the developed RMs with the reference values of the Curie temperature showed that they are consistent.

The theoretical significance of the results obtained is proof of the possibility of using the thermomagnetometric method for the development of certified reference materials of phase transition temperatures GSO 12005–2022/GSO 12007–2022. The possibility of applying the method of differential scanning calorimetry in determining the Curie temperature was also confirmed.

The practical significance of the results obtained allows expanding the possibilities for constructing the calibration dependence of measuring instruments for thermogravimetric analysis and monitoring its stability, as well as increasing the measurement precision of the Curie temperature of various substances and materials.

The need to improve pharmacopoeial approaches to the standardization of medicinal plant raw materials (MPRMs) and herbal medicinal products (HMPs), and the need to ensure the implementation of the principle of «cross-cutting» standardization in the series «medicinal plant raw material – phyto-substance – herbal medicinal product» determine the relevance of developing new, more rational approaches to the analysis of objects of plant origin.

The purpose of the research was the theoretical and experimental substantiation of the use of reference materials in the development of assay procedures on the example of certain types of plant raw materials and products based on it from the standpoint of the chemical composition, stability and physicochemical properties of the biologically active compounds contained in them.

Assay of active substances was carried out by high performance liquid chromatography (HPLC) using a Milichrome-6 chromatograph with a spectrophotometric detector in the ultraviolet (UV-) region. The UV spectra were recorded using a Specord 40 spectrophotometer. The measurement results were processed using the WinASPECT and Microsoft Excel 2016 programs.

As a result of research, procedures for assay of syringin in the bark of Syringa vulgaris, and in the rhizomes and roots of Eleutherococcus senticosus, rosavin and salidroside in the rhizomes and roots of Rhodiola rosea, arbutin in the leaves of Arctostaphylos uva-ursi and Vaccinium vitis-idaea, isosalipurposide in the flowers of Helichrysum arenarium, the amount of anthracene derivatives in fresh leaves of Aloe arborescens were developed and validated. Spectrophotometric methods for determining the amount of biologically active phenylpropanoids in terms of eleutheroside B (syringin) in MPRMs and HMPs of Eleutherococcus senticosus and the amount of aralosides in the roots of Aralia Manchurian were introduced. Based on the data obtained, the scientific rationale for the use of reference materials of syringin (Syringa vulgaris bark, Eleutherococcus senticosus rhizomes and roots), rosavin and salidroside (Rhodiola rosea rhizomes and roots), the sum of ammonium salts of aralosides (Manchurian aralia root), arbutin (Arctostaphylos uva-ursi and Vaccinium vitis-idaea leaves), mixtures of aloins A and B (Aloe arborescens fresh leaves) in the analysis procedures was provided. The concept of a systematic approach to the analysis of medicinal plant raw materials and products based on it was formulated.

One of the main parameters of sunflower seeds is its oil content. This characteristic is mandatory for certifica[1]tion of agricultural products and assessment of their value. IR spectroscopy and pulsed NMR methods are widely used to determine the oil content.

The purpose of the research was to scientifically and practically substantiate the possibility of using sunflower oil samples for calibrating NMR analyzers, identifying and assessing the quality of oilseeds and products of their processing based on the NMR method. The comparison of the results of various options for the calibration of a pulsed NMR analyzer for determining the oil content of sunflower seeds was carried out. The first option was to measure the NM relaxation characteristics of oil protons from prepared samples of sunflower seeds, followed by determination of their oil content by exhaustive extraction in a Soxhlet apparatus, construction of a calibration equation based on the obtained data, and entering its coefficients into the program of NMR analyzers.

The resulting calibration was the base one, with which other calibration options were compared. The second option was to use for calibrating the NMR analyzer various samples of sunflower oil obtained by pressing from sunflower seeds of the same varieties and hybrids, that were used for the first calibration option, as well as sunflower oil samples purchased in a commercial network. Five samples evenly distributed in the range from 2.000 g to 7.000 g with an accuracy of 0.001 g were taken from each oil sample using laboratory scales, and the amplitudes of proton NMR signals were measured in them. The dependency between the oil mass of the analyzed samples and the amplitude of proton NMR signals in them was graphed. Comparison of the obtained calibration dependences showed their close nature. Mathematical calculations have shown that the use of sunflower oil for the calibration of NMR analyzers does not lead to an increase in the error in the measurement results of the oil content of sunflower seeds compared to the first option of the calibration.

The practical significance of the research will considerably simplify the calibration process, reduce the calibration time from 3–4 days to 3–4 hours, and eliminate the use of toxic solvents and additional expensive equipment without a significant change in the error in determining the oil content of sunflower seeds by NMR.