Аннотация:Mercury is a naturally occurring element that has become an extremely hazardous pollutant as a result of exceeding natural levels in the environment due to intense human activity. Considered the safest and most economical technology, phytoremediation of soils contaminated with heavy metals has been actively studied by scientists in many countries since the end of the last century. This article presents a study of the vegetation of mercury-contaminated soils using a culture of white mustard (Sinapis alba), a new complexing agent. This is a study of a new chelating agent representing the class of polycarboxylic acids. The monoethanolamine salt of bitiodioacetic acid, in which the sulfur atom enters into the structure of the molecule and acts as a coordination partner for mercury, creates a high selectivity of the interaction. Studies have shown a pronounced effect of the chelating agent on the efficiency of mercury phytoextraction. In such cases, white mustard seedlings showed a good physiological state, increased development of biomass. The monoethanolamine salt of bitiodioacetic acid can be characterized as a highly effective reagent; however, more extensive testing is still needed to understand various aspects of its action.