Zinc oxide is the metal zinc that has been oxidized. The chemical formula is ZnO, 1 zinc atom and 1 oxygen atom held together by an ionic bond. Zinc oxide does occur in nature as the mineral zincite, but it is quite rare and commercially unavailable.
I have done a few stool samples in my time and have always just stored them in the fridge, until the next day to take them into the docs. Good luck hun I hope they get it sorted.
I kept half the tomatoes on the counter and half in the fridge. I conducted eight of the tastings after a roughly 24-hour storage period, and the remaining four tastings after two or more days of storage (with no tastings longer than 4 days of storage).