Disclosed are methods for the reduction of impurity metals from a refinery electrolyte solution. Certain methods comprise contacting a refinery electrolyte solution comprising an impurity metal with a phosphate ester having a structure represented by: wherein R1 comprises a linear, branched or cyclic alkyl or aryl group, and wherein the impurity metal is selected from the group consisting of iron, antimony, arsenic, bismuth, tin and combinations thereof.