A new method of gold concentration with a total enrichment factor of 104 has been developed. The method includes a liquid-liquid extraction of [image omitted] by reverse micelles; reduction of gold (III) to Au nanoparticles (with hydrazine monohydrate as a reducing agent) in the extracts and an electrophoretic concentration of the particles in a cell with parallel-plane electrodes. With increasing sodium sulfate concentration in the feed there was a decrease of water content for ordinary micelles and an increase of gold extraction. At a constant acid-salt background (3mol/L HCl+3.5mol/L Na2SO4) concentration, AOT introduction into micelles led to a decrease in extraction. The obtained regularities are consistent with a hydrate-solvate mechanism. The electrophoretic mobility of gold nanoparticles in extracts has been determined. When AOT was introduced into the extracts after the stage of reduction the electrophoretic mobility of nanoparticles was considerably increased (from -1.8x10-11 to 1.8x10-10m2/(Vxs)) which made possible an additional stage of electrophoretic concentration with an enrichment factor of 1.5x103.