Iron

• in vivo:

  Iron ingested in ferric (3+) state and converted to ferrous (2+) state via vitamin C in intestines to facilitate absorption; converted back to 3+ state via ceruloplasmin so it can be bound to transferrin (at normal body pH) to be transported to BM

  At BM, converted to 2+ to be incorporated into Hgb
• Specimens must be free from hemolysis, as hemoglobin will cause elevated results
• Colorimetric assay involves releasing from carrier (transferrin) in acid medium, reducing it to ferrous state with hydroxylamine and complexing it with ferrozine to form colored complex
• read at 560 nm