Center For Integrating Research and Learning

ArrowEye-eye, Popeye! Seeing Iron in Food

Try This At Home

Many foods contain iron, which blood cells need in order to carry oxygen. A protein called heme contains the iron (II) ion at its center. Blood vessels in the lungs, where oxygen concentration is high, allow the heme to bond to the oxygen molecule to create oxyhemoglobin, which is then transported to oxygen-hungry tissues throughout the body.

Because iron is so important to your body, you need to make sure you get enough in your diet! In this activity you will use a magnet to separate the iron contained in some iron-rich foods.

What you’ll need:

  • Cereal or other food with iron (Total Cereal or Gerber Graduates Arrowroot Cookies work great)
  • A Ziploc bag
  • A little water
  • A plastic, see-through cup
  • A magnet
Cereal and magnet

What you'll do:

  1. Pour some of the food into a Ziploc bag. Seal the bag with as little air in it as possible, then mash the food until you make a powder.
  2. Fill the bag with some water and mix.
  3. Let the mixture sit for at least one hour.
  4. After the cereal mixture has been allowed to sit, pour some into a plastic cup.
  5. Move a strong magnet against the side of the cup for about a minute. You should observe iron particles collecting on the side of the cup!

Did you know?

Question Mark
  • Breathing carbon monoxide (such as car exhaust) is dangerous because it binds to the iron in the heme molecule about 200 times tighter than oxygen does. This kicks those needed oxygen molecules out of the way, possibly leading to suffocation.
  • How much iron you need in your diet depends on your age and gender. Teen and adult women need about 15 milligrams a day. Teen and adult men need about 10 milligrams a day.

Think Quick!

Reorder the below list of foods, starting with the one that has the most amount of iron per serving and ending with the one with the least.

  • Scallops
  • Dried apricots
  • Peanut butter
  • Cooked spinach
  • Strawberries
  • Blackstrap molasses
  • Cheese pizza
  • Instant oatmeal
  • Steak
  • Black beans
1. Blackstrap molasses: 10.1 mg
2. Instant oatmeal: 6.7 mg
3. Cooked spinach: 6.4 mg
4. Dried apricots: 3 mg
5. Steak: 2.6 mg
6. Black beans: 2.5 mg
7. Scallops: 2.0 mg
8. Cheese pizza: 1.6 mg
9. Strawberries: 0.6 mg
10. Peanut butter: 0.3 mg

For more information contact Carlos Villa at or (850) 644-7191.

© 1995–2014 National High Magnetic Field Laboratory • 1800 E. Paul Dirac Drive, Tallahassee, FL 32310–3706 • Phone: (850) 644–0311 • Email: Webmaster

NSF and State of Florida logos NSF logo State of Florida logo

Site Map   |   Comments & Questions   |   Privacy Policy   |   Copyright   |   This site uses Google Analytics (Google Privacy Policy)
Funded by the National Science Foundation and the State of Florida