Tanned Vitamin C

[Ray Rogers]

Does anyone have experience with Vitamin C "tanning" ?

I placed a small quantity of ascorbic acid in a plastic zip lock bag and the bag in contact wth the drug "Allegra"... within a relativly short time (days) the Vitamin discolored to a nice light tan....

I need to confirm these observations, but prelminary observations seem to confirm this actually happened due to the Allegra -
but I have not ruled out simple moisture or even the plastic yet...

Anyone else with discolored "C" from any cause?
Or know what's going on?

:confused:

 

[Aurum]

I'd hazard that it is moisture and air in the bag. Doesn't take much for Vit C to discolour.

In solution its also Iron sensitive, however the usual cure for that (EDTA and derivatives), decompose it to a nice discoloured mess even faster (!)

 

[mabman]

Not quite sure what you mean to "...and the bag in contact with the drug Allegra.." - do you mean you had Allegra in the bag at the same time as the Vit C?

I took Allegra for a while and was surprised to read the non-medicinal ingredients included iron oxide (rust) and silicon dioxide (sand) - apparently this isn't terribly uncommon in anti-histamine pills, at least. So, I'm not sure how it works chemically but I would imagine some cross-contamination would occur if you have both Allegra and Vit C in the bag at the same time.

 

[AgX]

Was it a dark-reaction or was light involved. As we are on a photographic forum....

 

[naeroscatu]

Was it a dark-reaction or was light involved. As we are on a photographic forum....

Yes, I was tinking along those lines too; how is this related to photography.

 

[Aurum]

I took Allegra for a while and was surprised to read the non-medicinal ingredients included iron oxide (rust) and silicon dioxide (sand) - apparently this isn't terribly uncommon in anti-histamine pills, at least. So, I'm not sure how it works chemically but I would imagine some cross-contamination would occur if you have both Allegra and Vit C in the bag at the same time.

Iron oxide is widely used as a colouring agent, and will give tones between Brick red and chocolate brown.
Silica is an anti-caking agent. Again widely used, and allows the powdered tablet to be processed easily before being shaped and stamped.

Silica can be quite acidic, and Iron oxide can react with acidic powders.
Tablets tend to be coated though, so contact between them and Vit C would be limited

 

[Kirk Keyes]

And coated with gelatin fairly often.

 

[Ray Rogers]

Yes, I was tinking along those lines too; how is this related to photography.

Well...
The Vitamin is a developing agent and I packed it for use in the field.
I put the Allegra in my camera bag just before leaving home...
when I opened the developer, I noticed the discoloration.... and was curious.

 

[Ray Rogers]

Was it a dark-reaction or was light involved. As we are on a photographic forum....

:confused: low level light was occasionally present.
but I suspect what ever it was, it was a dark rxn.

 

[Ray Rogers]

I'd hazard that it is moisture and air in the bag. Doesn't take much for Vit C to discolour.

In solution its also Iron sensitive, however the usual cure for that (EDTA and derivatives), decompose it to a nice discoloured mess even faster (!)

If this is true then it might be the explanation...