Science Buddies: "Ask an Expert"

I am doing my 7th Grade science project on fruit ripening and the plant hormone ethylene. I need to test the presence of starch. The experiment protocol calls for a iodine starch solution using a combination of 2% potassium iodine solution and 2% iodine solution mixed with water. I have discovered that potassium iodine is a restricted solution and not available for purchase by individuals. I have researched other alternatives and want to know if these are workable. One is to use iodine mixed with ethanol (rubbing alcohol). I have a stabilized iodine solution so wonder if I can use that in combination with ethanol to create the iodine stain solution. My project is due next week so any assistance you can offer is greatly appreciated.

SO

In my high school biology classes, to test for starch our labs used the Lugol's solution. Does your science teacher have some that you can use? Or can you bring your samples to school and perform the experiment under supervision? Ask you teacher for more direction for the safe way to conduct this experiment.

Always check the safe handling of chemicals.

This is an interesting experiment

Yvette

Thank you very much. I will talk to my science teacher. I did read on-line about another starch test using povidone-iodine and rubbing alcohol. I'll ask my science teacher about this alternative as well.

SO