Oxalic acid dihydrate is a reducing agent. Oxalic acid, also known as Ethanedioic acid is a diprotic acid, which means it can give away 2 protons (hydrogen ions) to a base. Oxalic acid dihydrate has been evaluated as a treatment for reducing populations of naturally occurring microorganisms. Used as a buffer in chromatographic separation, dechelation and deproteinization in tandem with acetonitrile and/or other solvents.