Biological functions of cobalt and its toxicology and detection in anti-doping control

Objectives. Over the last decade, hematopoietic stimulants have grown increasingly popular in elite sports. This is supported by the growing number of high-profile doping scandals linked to their use. A group of these stimulants includes cobalt salts, which cause an increase in the oxygen capacity of the blood as well as a powerful stimulation of metabolic processes, resulting innoticeable competitive advantages. The use of cobalt salts is regulated according to the Prohibited List of the World Anti-Doping Agency (WADA). Currently, only a few works have been dedicated to solving the problem of detecting the abuse of cobalt salts in anti-doping control. Only a few laboratories have included cobalt salt determination in their methodological bases. The purpose of this review is to attract the attention of the scientific community to the toxicity of cobalt compounds, consequences of their intake, and pharmacokinetics, as well as the problems in their detection methods due to their widespread availability in the modern market and the growing number of abuse cases.Results. The main biological functions of cobalt, cellular levels of exposure, toxicity, and symptoms of cobalt salt poisoning are presented in detail in this review article. The data from the literature on the main methods for detecting cobalt as a doping agent have been generalized and systematized. There is a major focus on the amount of cobalt in dietary supplements that could cause an athlete to test positive for cobalt when they are consumed.Conclusions. After analyzing promising cobalt detection approaches and methods, it was determined that high-performance liquid chromatography in combination with inductively coupled plasma mass spectrometry has an undeniable advantage for detecting cobalt as a doping agent. The lack of explicit WADA requirements for detection methods and the lack of its obligation to determine cobalt make it tempting for unscrupulous athletes to use its salts. Therefore, antidoping laboratories must implement the abovementioned method as soon as possible.

Research Trends Analysis on Subject Materials Science for Energy Engineering by Scopus Data

The objective of this article: analysis of research trends on the topic "Materials Science for Energy Engineering" for the period 2012-2021. Materials and methods: bibliometric analysis of data from the Scopus abstract database.Results. It is shown that this topic is developing faster than the general energy topics.The key feature of the research trends is a significant increase in work on the development of materials for renewable energy and a decrease in the number of publications related to nuclear power.The primary goal of many studies is to increase the efficiency of renewable energy production through the use of new materials.The importance of the topic is evidenced by the emergence of new journals that quickly entered the first quartile of the abstract databases Scopus and Web of Science, for example: ACS Applied Energy Materials.There has been a significant increase of interest in perovskite solar cells, layered semiconductors, triboelectric nanogenerators, cobalt compounds, sulfur compounds, and oxygen and hydrogen evolution reaction during Electrolysis.Publications on electric batteries are well represented in all time intervals. The focus is on electrode materials and battery efficiency.

Determining patterns in the use of finishing formulations for trimming the Crust leather

This paper has considered the possibility of using new finishing formulations to finish the Crust leather, manufactured from cattle raw materials aimed to finish shoes and leather garments.The quality indicators of finishing formulations and their elementary chemical composition have been investigated. It was found that the finishing formulations possess a high covering capacity due to the presence of mineral pigments in their composition. X-ray fluorescent analysis has proven that the presence of chromium pigments and copper compounds renders the green color to the composition; the compounds of cobalt, copper, iron, chromium ‒ blue color; cobalt compounds ‒ reddish-brown color.It has been established that the finishing formulations are resistant to the effect of electrolytes of different nature over a wide pH interval, from 2 to 11.When determining the uniformity of the composition by using a chromatography method involving fan-shaped paper, it was found that the composition of blue has a pronounced purple hue, of reddish-brown – red.The effectiveness of the use of finishing formulations to finish the Crust leather has been proven by determining the indicators of its quality. The finishing formulations give the Crust high resistance to dry (exceeding 500 rotations) and wet friction (exceeding 150 rotations), multiple bending (exceeding 50,000 rotations), the effect of water (2 to 5 points), and organic solvents (2 to 4 points). At the same time, the finishing formulations are characterized by rapid diffusion into the structure of the leather with a natural front surface with the simultaneous provision of specific properties to it. Specifically: water-repelling properties (hydrophobicity), shine, wax grain, matte, saturated homogeneous color. The leather with the introduced finishing formulations does not require fixing the resulting coating with water-based varnish.It is recommended to use the finishing formulations in the production of Crust leather shoe top by applying them onto the surface by spraying or using a brush to create the desired effect

OXIDATIVE ROASTING OF INDUSTRIAL SPENT CATALYSTS CO-Mo/Al2O3 HYDROPROCESSING WITH LIM

The oxidative roasting of industrial spent catalyst Co-Mo/Al2O3 for the hydrotreatment of diesel fuel with lime in an air atmosphere was studied. Using the data of DTA, TG and X-ray phase analysis, it was found that during roasting, the sulfur and carbon oxides forms CaSO4 and CaCO3, and Mo is converted to calcium molybdate. Using the filtering fixed bed of reagents, the kinetics of roasting was studied. It was found that in the temperature range of 550 – 600 °C with air, supply rate of 3 l/min the process ends in 38 - 44 min for ground and non-ground catalyst. The optimal parameters (lime consumption, temperature, and time of roasting) of the absorption of sulfur oxides during roasting were determined. The degree of sulfur and carbon oxides adsorption is 96 and 36%, respectively. Separation of roasting products using unmilled spent catalyst is proposed into a small fraction (contains a mixture of CaSO4, CaCO3 and CaO) and a coarse (consists of Al2O3, CaMoO4, CoO) fractions, and their separate processing. It has been shown that in the separate processing of roast fractions by a sodium carbonate solution, it is possible to separately obtain alumina (catalyst base) with cobalt oxide, a molybdenum-containing solution, and also a mixture of sulfate, carbonate and oxide calcium. The used method of roasting the spent hydrotreating catalyst with lime will allow hazardous waste of hazard class 3-4 to be disposed of without hazardous waste gas costs. It allows one to obtain, during further processing, molybdenum and cobalt compounds, as well as finely divided alumina.

The Initial Surface Structure of Co3O4 as a Factor of Influence on Kinetic Features of the Dissolution of the Solid Phase

Due to the depletion of natural reserves of cobalt-containing ores, it is urgent to optimize the processes of cobalt replenishment, based on the leaching of its compounds, processing of industrial waste, regeneration of cobalt compounds from catalysts. The kinetic characteristics of the dissolution of metal oxides are influenced by the initial state of their surface structure, which requires the accumulation of experimental material and individual targeted studies. The paper presents the results of an experimental study of the surface structure of industrial Co3O4 cobalt oxide samples. The studies were carried out by electron microscopy and X-ray phase analysis and revealed the size and shape of the Co3O4 particles and the nature of their surface distribution. The correspondence of experimental and theoretical data has been established, Co3O4 cobalt oxide has been identified as an α-form of the cubic crystal system. The data obtained are of interest in the study of the effect of the surface characteristics of the solid phase of Co3O4 cobalt oxide on the dissolution kinetics under the chemical and electrochemical influence

Restricted active space simulations of the metal L-edge X-ray absorption spectra and resonant inelastic X-ray scattering: revisiting [CoII/III(bpy)3]2+/3+ complexes

The metal L-edge spectra of cobalt compounds have been interpreted through restricted active space calculations.