The article discusses the features of using the mass balance (MB) method widely used in the Russian Federation to determine the purity of a selected group of organic components – such substances, and the MB model was adapted for substances suitable for separation or purification by distillation. Then an optimized algorithm for determining the purity of these components was developed. The operability and efficiency of the proposed approach is demonstrated on the example of benzene. The approach included the MB model and research algorithm. It has been successfully implemented on the State Primary Standard GET 208; the units of the mass fraction of the main component in benzene, toluene, n-heptane, isooctane, n-dodecane, n-hexadecane, propane‑1, propane‑2, n-octanol are reproduced using the algorithm. Certified pure substances were used to create certified reference materials (CRMs) for the composition of the corresponding organic compounds. The proposed approach can be applied in the future for the rapid expansion of the list of GSOs for the composition of organic components

Pollution of agricultural soils with heavy metals is an acute problem both in Russia and globally. The use of standard methods for soil monitoring is hampered by the need to regularly modernize monitoring equipment. Therefore, the development of matrix multicomponent reference materials (RM) for the composition of soils contaminated with heavy metals in concentrations exceeding their limiting values in natural soils is a highly relevant research task.
To develop in-house multicomponent RMs of soil composition with the certified value of mobile forms of copper, zinc, lead, cadmium, nickel, cobalt and manganese in concentrations exceeding their trace levels.
Soils for the development of RMs were collected in residential areas of the Vladimir Oblast and Chelyabinsk Oblast subjected to technogenic pollution. Samples were prepared according to a conventional methodology. The metrological characteristics of the developed RMs were determined by the method of interlaboratory comparison with the participation of 59 accredited testing laboratories. The mobile forms of heavy metals were determined by the atomic absorption method. An assessment of the error and uncertainty of the certified RM value was performed.
Two in-house RMs of the composition of soils containing mobile forms of copper, zinc, lead, cadmium, nickel, cobalt and manganese at the level of tens of maximum allowable concentrations were developed. The developed RMs were found to be homogeneous in terms of all certified indicators. The calculated error did not exceed admissible values. The shelf life of RM samples was determined to be two years.
The developed in-house RMs can be used for supporting agroecological monitoring and research programmes.

This article studies the development of measurement procedures based on various methods for a comprehensive analysis of the carbohydrate composition of food systems. The basis of the primary reference measurement procedure (PRMP) is the method of iodometric titration based on the ability of iodine to oxidize aldosaccharides to the corresponding uronic acids in an alkaline medium. The accuracy of the PRMP was improved by optimizing the measurement parameters, including the method of high-performance liquid chromatography with refractometric detection (HPLC/RD), and by establishing their possible variation limit based on a multifactorial experiment. The application of the PRMP made it possible to measure the mass fraction of carbohydrates (total sugar) as the sum of the mass fractions of reducing and non-reducing sugars in milk and dairy products, grain and milk products, low-lactose and lactose-free products, including those used for preparing baby food. In order to further detail the carbohydrate composition, highly selective methods were developed for measuring the mass fractions of lactose and galactose by the spectrophotometric (enzymatic) method, and the mass fractions of mono- and disaccharides by the HPLC/RD method in milk and dairy products. It was found that the measurement results of both the total content of carbohydrates and individual mono- and disaccharides in the samples of milk and dairy products obtained by various methods (iodometric titration, HPLC/RD, enzymatic method, refractometry, IR spectroscopy, calculation method) are consistent with each other subject to the stated uncertainties. Thus, the applicability of the developed PRMP in combination with other methods for conducting an in-depth analysis of the carbohydrate composition of milk and dairy products was confirmed. The developed procedures were used to characterize reference materials for the composition of dairy products (3 types), mono- and disaccharides (9 types).

The accumulation of electronic waste (e-waste) on the ground leads to environmental pollution with toxic metal ions, which subsequently harms all living organisms. Many countries still use hydrometallurgical or manual methods to extract silver ions from e-waste. These methods are unsustainable and highly toxic; therefore, it becomes necessary to introduce new environmentally compatible methods for separating valuable components from objects of various compositions. This article proposes an environmentally compatible method for the extraction of silver ions from multicomponent systems using poly(N-thiocarbamoyl‑3-aminopropylsilsesquioxane). The sorbent surface was studied by Fourier-transform infrared spectroscopy using an attenuated total internal reflection accessory. The concentration of grafted thiourea groups is 1.39 mmol/g according to elemental analysis. It has been determined that this sorbent is capable of quantitatively extracting silver ions in the pH range from 0 to 6 at a concentration of silver ions in the initial solution of 1·10–4 mol/dm3; the static sorption capacity for silver ions under experimental conditions reaches 1.22 mmol/g. When sorption is carried out in dynamic mode, the value of the dynamic capacity before breakthrough is 0.046 mmol/g, and the value of the total dynamic capacity for silver ions is 0.132 mmol/g. The highest desorption (71–78 %) is achieved using sulfuric acid solutions with a thiourea concentration gradient.

The article deals with issues related to the improvement of the metrological support system in the field of vacuum measurements in the works of D. I. Mendeleyev Institute for Metrology (VNIIM). The relevance of vacuum technology and vacuum measurements for the industry of the Russian Federation is substantiated. The author shows the trends and strategies that dominate in this area in a historical retrospective. The main stages and results of theoretical and practical research work in the field of vacuum measurements carried out at the D. I. Mendeleyev Institute for Metrology (VNIIM) in recent years are described. It is emphasized that in the scientific community of the Russian Federation and D. I. Mendeleyev Institute for Metrology (VNIIM) there is a huge heuristic potential and a solid material base that allow us to expect the latest progressive approaches and solutions in the field of metrological support of vacuum measurements