The determination of ferrous iron in natural waters with 2,2′ bipyridyl

Measurements of ferrous iron, in water containing both ferrous and ferric iron, by the 2,2′ bipyridyl method and polarography are compared. When samples are protected from strong solar irradiation and contact with air, and measurements are made quickly, the 2,2′ bipyridyl method can distinguish the oxidation states of iron in anoxic waters containing ferrous iron.