I have grown turmeric from root, from a specialist Asian food store, I would not worry about chemicals preventing the turmeric from sprouting, they put Dihydropyridazine on a lot of vegetables to stop them from sprouting, but it they still sprout eventually.
Buy a piece of turmeric from an Asian food store, give it a scrub with some cold water and a sponge, then rinse thoroughly, pat it dry with a towel, you really need to get it dry otherwise it will rot. Then I would leave it somewhere warm where is gets some sunlight but not too much. When you see it start to sprout put it in a small pot, and bury it just under the surface, the point of sprouting should be just beneath the surface.
Keep the soil moist but not wet, and keep it somewhere warm, but not in direct sunlight.