Vitamin C oxidation question

[britmicro]

Hi Sarah,

I have noticed that my clothes and sheets are being marked/stained by the vitamin c that I am applying to my neck, chest, stretch marks, etc. (not permanently, it washes out with detergent). The 'staining' looks and smells a lot like fake tan, with an orangey colour. I imagine this is from the oxidising of the vitamin c on the clothes during the day. I make the vit c exactly as you recommend, 1 part powder to 19 parts boiled water and keep it in the amber bottle in the fridge, making a new batch every 5 days. When I apply it, it is a clear liquid. I pat it on my skin like a toner, with my fingers.  Does this mean that it is oxidising on my skin?  Or just on the clothes? I have heard that having oxidised vit c on the skin is bad, so I want to avoid that.

[SarahVaughter]

It should definitely not oxidise that fast, but perhaps there is a rare, special condition why it does in your case, such as a high concentration of a certain metal in your drinking water or your clothes.

You could do a test: Put a little of the solution on a plate and observe how long it takes to turn orange. It should take more than a week.

If it goes faster, it has something to do with the water or how you diluted it.

We think there is a chance that if you have oxygen- or iron-rich water water and you mix that water at a very high temperature with the vit. C, that it may degrade faster.

So please try to mix it when it's colder - preferably with water that you have first boiled to expel the dissolved oxygen.

Our best guess (my husband has a Chemistry PhD) is that your clothes contain a catalyst to the degradation of vit. C.

Perhaps they contain metal-based dyes that are responsible.

One way to avoid the problem is to wait until the vit. C has been partially absorbed into your skin (30 to 60 minutes) and then lightly rinse off the excess, not using too much water so that you won't vigorously expel the vit. C again from the skin.

[bigmouth]

I have read this question and answer and would like a more definitive way to tell if my vitamin C is oxidized or not.
I make according to directions but using the Vitamin C primarily on my face 2-3/per week...it lasts at least 4-6 weeks
or more. I don' keep in the fridge b/c its not convenient but will if necessary. But would like to know how long
you think each batch should last, both refrigerated and not refrigerated.  I can't imagine that others are going
through theirs much more quickly than I am as the bottle as 10 teas. is a lot of liquid.  Is there a way to tell if its oxidized because
I heard oxidized can age skin...thank you.

[SarahVaughter]

You should keep the vit. C serum in a small airtight container and preferably in the fridge. Never store it in direct sun.  Make smaller batches more frequently if you want to be sure.  Check the color of your serum - it should be transparent, not yellow or orange.