Аннотация:The ratio of the content of humic acids (HA) to the content of fulvic acids (FA) can be used as an index of the degree of humification of humic substances (HS). It is possible to determine the HA/FA on the basis of determining the amount of organic carbon contained in the composition of humic acids or fulvic acids - CHA/CFA. The classical method is the Tyurin method, which consists in the oxidation of all organic substances of the studied fraction of humic substances with an excess of a solution of potassium dichromate in dilute sulfuric acid with further determination of the amount of dichromate remaining in the solution. Now there are more advanced methods, for example, the method of determining TOC (Total Organic Carbon). The method of determining TOC allows analyzing large batches of samples faster.