By this time, Standard Oil had also become interested in the desulphurization process after moving production to oil fields in Ohio that had a similar sulphur content to Lambton County. In 1886, Standard Oil persuaded Frasch to return to the United States and join their company by offering "a salary higher than that of any other scientist in the country", and an exchange of his shares in the Empire Oil Company for an equivalent amount in Standard Oil. After returning to the United States, Frasch perfected his desulphurization strategy, and Standard Oil held a monopoly on the process until 1905.Hill, Alan. (1979) Historical Foundation of Canada's Oil Industry and the Development of Imperial Oil Limited from 1880-1920 (Master’s Thesis). The University of Manitoba. p. 102-103 The loss of Frasch and the desulphurization process was a major blow to the long-term future of Imperial Oil.Hill, Alan. (1979) Historical Foundation of Canada's Oil Industry and the Development of Imperial Oil Limited from 1880-1920 (Master’s Thesis). The University of Manitoba. p. 104.
