Product Introduction 3-(2-Pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4′′-disulfonic acid sodium salt is a highly specific water soluble reagent. Used in the accurate determination of sub microgram levels of serum iron. (ie. reagent for the spectrophotometric determination of Fe). 3-(2-Pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4′′-disulfonic acid sodium salt also known as Ferrozine is a chelating agent for ferrous iron. Application It was used in determining of chelating activity of Fe2+ using Boyer and McCleary method.