The determination of total protein in plant samples is a difficult task, as classical nitrogen-based methods are not selective for the nature of nitrogen, and the results of biochemical methods are influenced by both associated compounds and the complex composition of the protein matrix. Using electrophoretic separation of three commercial sunflower protein samples, it was determined that the studied proteins are a mixture of salt-soluble globulins and water-soluble albumins of different molecular weights. The total protein content of the studied samples was determined using five spectrophotometric methods: direct spectrophotometry, bicinchoninic acid assay, and Benedict’s, Bradford’s, and Lowry’s methods. After comparing the results obtained, it was concluded that, for the determination of protein in these plant materials, the use of the Dumas nitrogen-based method in tandem with Lowry’s spectrophotometric method is the most suitable.

Water quality control employs techniques mostly targeting individual analytes; group detection is also practiced, but the choice of group methods is limited, which supports interest in developing such methods. We have examined the interaction of hypochlorite with a chlorine-containing heptamethine carbocyanine dye in the presence of 30 organic and inorganic model analytes that were found to induce diverse color changes in the system. The main supposed mechanisms are retardation of the dye oxidation with hypochlorite (presumably by scavenging chlorine radicals) and substitution of chlorine atom in the dye by the most nucleophilic analytes (amines, amino acids, proteins, DNA, phenol). The grass-green substitution product is more contrastingly visible against the dark-purple hypochlorite oxidation product of the dye than against the original emerald-green dye. The indicator reaction is monitored photographically for 10–40 min and the images are processed using principal component analysis (PCA) or linear discriminant analysis (LDA), allowing for data convolution for the complex color transitions. Nitrogen compounds are discriminated from the others, and more reactive analytes (tryptophan, cysteine, bovine serum albumin, and DNA) are detected in the presence of less reactive ones in natural water. The system is promising for the development of group assays for dissolved organic matter and the discrimination of water samples.

Possibility of detecting non-specific pollution events in water sources by daily monitoring. The optical signal of an indicator reaction carried out in a 96-well plate is obtained by photographic recording with subsequent chemometric data processing.

Africa’s rapid socio-economic development makes the problem of access to clean water in the region extremely urgent. The need to improve the relevant infrastructure is recognised not only at the level of national governments, but is also becoming an important task for international development institutions, including African ones. In particular, the African Development Bank Group has created the “Water Strategy 2021–2025”. The article collects, systematises and analyses quantitative indicators that reflect the access of people and economic sectors to clean water, as well as the financing of this area and its place in global (Sustainable Development Goals 2015–2030, Millennium Development Goals 2000-2015) and African (“Agenda 2063”) strategies. The authors of the article conclude that modern African approaches to expanding access to clean water and new infrastructure projects imply efficient and systematic use of water resources not only within the national borders of the countries, but also at sub-regional and macro-regional scales. In terms of Russian-African partnership, in addition to investments in infrastructure, technology transfer can play a special role. The priority African markets for the introduction of Russian technologies in the field of water treatment and purification include the countries where the water problem is the most acute and oriented towards cooperation with Russia, in particular, Burkina Faso, Niger, Egypt, Sudan, Algeria, and Zimbabwe.

Today, there is a serious competition between foreign investors in Africa. Russian companies also have foreign economic interests in the continent, which requires studying the experience of other states, namely their country and sectoral priorities and the instruments used. Human geography lacks a generally accepted framework for analyzing the geography of investment from the perspective of donors rather than recipients of capital, which is why it is proposed in this paper. After specifying the relationship between the main terms in the field of investment (foreign investor activity, investment image, investment climate, etc.), the article provides a consistent scheme of geographical macroregional analysis of this sphere using tile maps as the most productive means of visualizing spatial information on investment at a given hierarchical level. After identifying the spatial and sectoral patterns of activity of different investment donor countries in Africa, an attempt is made to reconstruct the factors that have predetermined the spatial and sectoral differentiation of direct investment in the countries of the macro-region. A typology of capital-exporting states (‘ubiquitous’, ‘satellite’, ‘cultureoriented’, ‘European colonial powers’, ‘intra-regional leaders) that can be applied (both partially andfully) to other continents is proposed.

At the current stage of development of international economic relations, the role of the ocean’s economy is increasing. The rational use of ocean resources will contribute to the economic development of the countries of the Global South and Russia in the 21st century. However, in the absence of statistics, comparative assessment of the oceans economy’s potential of different countries becomes difficult. Thus, the purpose of this article is to propose a path for such an assessment (for the case of African countries). Based on V. Podinovskiy’s theory of criteria importance and related methods, the authors’ methodology for assessing the Oceans Economy’s Potential (OEP) is proposed. The following OEP indicators are suggested based on the interpretation of the World Bank’s “economy size” indicators: total population; area of the exclusive economic zone and inland waters; and GDP of coastal area (the multiplication product of PPP GDP per capita by the number of people living within 10 km of the ocean coast). In the first stage, the comparison is based on absolute indicators; in the second stage, these were converted into scores. As a result, African countries with the highest OEP are defined: Egypt and South Africa have the highest first-order potential, and Madagascar, Mauritius, Nigeria, Seychelles and Tanzania have the highest second-order potential. The prospects for their cooperation with Russia are assessed. The proposed approach can be used for comparative assessments in different regions of the world. The possibility of using the proposed OEP assessment method for water treatment and purification projects is also noted, but the methodology can be refined for these purposes.