Hello /sci/. I come to you in a time of need. I am creating a tincture with a certain molecule that is soluble in water, but oxygen dissolved into the water decomposes the active ingredient in my tincture.
I cannot use ethanol for this purpose because I am already using it to dissolve another ingredient. And quite simply I need water any way to dilute the ethanol.

What can I use that will prevent or at least slow down oxidization of my water but is also safe for human consumption?

Here is a Terra for your time.