A system includes a turbine combustor and one or more supply circuits configured to supply one or more fluids to the turbine combustor. The one or more supply circuits include at least a liquid fuel supply circuit fluidly coupled to a liquid fuel source and configured to supply a liquid fuel from the liquid fuel source to the turbine combustor. The system also includes a corrosion inhibitor injection system including a magnesium source storing a magnesium-based inhibitor that includes magnesium oxide (MgO) and an yttrium source storing an yttrium-based inhibitor that includes yttrium oxide (Y2O3). The corrosion inhibitor injection system is fluidly coupled to the turbine combustor and the one or more supply circuits, and is configured to inject the magnesium-based inhibitor and the yttrium-based inhibitor as vanadium corrosion inhibitors into the turbine combustor or the one or more supply circuits.