A high performance liquid chromatography method to routinely and reproducibly detect and quantitate metal complexes is provided. The metal complexes used in the method of the invention can be different metal complexes, or they can be stereoisomers of the same metal complexes. The high performance liquid chromatography method of the present invention is suitable for the separation of diastereomers of the same metal complexes. Also provided is a chiral high performance liquid chromatography method to separate enantiomers of metal complexes. Superoxide dismutase mimetic compounds are also provided.