Sentiment analysis is a tool used in many areas (marketing, management, sociology) and its effectiveness depends on the quality of sources and the volume of data gathered. The authors present procedures that allow the collection of large volumes of text data and the processing thereof, the result of which is a quick (practically in real time) assessment of emotions and their changes. In the example analysis Russian sources are given (in the Russian language, creating a system of media monopolised by the authorities). The analysis was between week 1 and 17 of 2022 - before and during the conflict between Russia and Ukraine. The results obtained, trends of changes in sentiments pertain to Presidents Joe Biden, Andrzej Duda, Aleksandr Lukashenko, Emmanuel Macron, Volodymyr Zelensky and Vladimir Putin - the results are emotionally charged figures of presidents created for the internal purposes of Russia and provide significant information for analysts of the ongoing conflict. Obtaining similar results without the use of information technology is practically impossible. Sentiment analysis of large resources makes it possible to detect the change dynamics that are difficult for a human being to capture (a person analysing source materials). Concurrently, the cost and time of obtaining results recommends the described method as supporting analytical work.