Science Buddies: "Ask an Expert"

Hello, My name is wang. I am currently doing a project for my school that requires me to test for iodine in different types of salt. I have tested sea salt, kosher, table salt(iodized) and himalayan pink salt.
The results for the ts and the pink salt were however very questionable and confusing. The ts turned into a dirty pink color and the pink salt turned gray and smokey and black after I used liquid starch, iodine antiseptic solution, hydrogen peroxide, white vinegar, etc to test for the presence of iodine. I am confused as to what approach I should take to start doing the research so I was hoping I could get some idea here.

Thank you in advance.

Hi Wang, When you tested the table salt, you got a pinkish/blue result, which indicated the presence of iodine. The label of the table salt probably says "iodized salt", and your result confirmed it. The results from testing sea salt and Himalayan salt indicated the absence of iodine, or the levels were so low they didn't register on your test results. Maybe try testing a few salts that are specifically labeled as iodized, so you can see what the results should look like when there is iodine present. This info might help: https://www.scientificamerican.com/arti ... dine-salt/