Here’s an idea for a summer practical to test out your digital microscopes or visualisers. I’m sure you know that some of the foods we eat are “fortified” with extra iron. What’s not always known is that it is possible to use a strong magnet to extract this iron and take a look at it.
Get yourself a breakfast cereal with the highest amount of iron you can find. Check the nutritional labels for the highest amount of iron per 100g.
1. To extract the iron, first put the cereal into a large, sealable sandwich bag.
2. Then, use a rolling pin to smash the cereal into a fine powder.
3. When the cereal is a dust, transfer into a new bag. This is important as the bag you were originally using will now almost definitely be full of tiny holes
4. Fill this new bag with water until the cereal forms a messy, swimming, paste.
5. To extract the iron I used a very strong, small magnet. The one I used came from a set that I used to hang photos onto metal wires. To make it easier to handle I stuck mine to the head of a screw.
6. Fish around in the paste with the magnet for a few minutes. Make sure you trawl the whole bag.
7. Carefully clean the magnet in a bowl of clean water and gently pat dry.
8. The iron filings won’t be visible to the naked eye, but if you use a digital microscope (even a very cheap one) you should be able to see them.
8. The iron filings should be visible on the magnet. There’s wasn’t lots, but there was enough to be visible. You should just be able to see some along the edges of the magnet.
And that’s it. Proof that makers of breakfast cereal do indeed add extra iron into your food – and it’s possible to see it!
Kibble, B (2010) Iron in Cereal, Let’s take a look at it. School Science Review, 92 (339), 10-11