[en] The adsorption of isomers of aminobenzosulfonic acids (ABSA) and products of their interaction with formaldehyde on mercury electrode and their inhibiting action on discharge of cadmium and zinc ions on mercury-dropping, cadmium and zinc electrodes is studied. It has been found that the investigated ABSA isomers are weakly adsorbed on the mercury electrode surface and practically exert no influence on the Cd²⁺ and Zn²⁺ ion reduction rate. The products of their interaction with formaldehyde possess high adsorption capacity in the wide range of potentials and considerable inhibiting action on the Cd²⁺ and Zn²⁺ ion discharge