Iron Assay

Iron is an element that plays an essential role in a number of biological processes. Iron is bound to several proteins such as the oxygen-transporting hemoglobin in the red blood cells and oxygen storage protein myoglobin in the muscle. It is also stored by ferritin and hemosiderin. Inorganic iron contributes to redox reactions in the iron-sulfur clusters of many enzymes, such as nitrogenase. In this colorimetric assay, ferric carrier protein will dissociate ferric into solution under acidic conditions. After they are reduced to the ferrous ions, these ions react with chromogen to produce a stable colored complex and give absorbance at 590 nm. The color intensity thus formed is directly proportional to the concentration of iron in the sample. A specific chelate chemical is included in the buffer to block copper ion interference.