How do I convert the first into the second?UnintentionalChaos - 12-12-2007 at 08:59
Zinc citrate is insoluble, zinc gluconate is.....Mr. Wizard - 12-12-2007 at 09:04
Quote:
Originally posted by UnintentionalChaos
Zinc citrate is insoluble, zinc gluconate is.....
I think he means you add Citric Acid to a solution of the Gluconate vulture - 12-12-2007 at 12:58
Making zinc citrate is not an easy task as this is actually a zinc complex which needs exact stoichiometric ratios and pH to be prepared. It's of
great interest for making reliable ZnO coatings in several applications, I'm sure there's literature to be found.Nixie - 13-12-2007 at 01:39
Got any leads?Nixie - 13-12-2007 at 01:43
Quote:
Originally posted by UnintentionalChaos
Zinc citrate is insoluble
Random site I see says 2.6 g per liter... not exactly insolublenot_important - 13-12-2007 at 06:19
Usual way to make the di or tri hydrate is to react zinc carbonate or oxide with citric acid. I don't think you're going to go directly from
gluconate to citrate, time to get out the box of bicarb. Google books should be able to locate an older chemistry book with details on making the
carbonate.Nixie - 29-3-2008 at 23:46
I didn't manage to find anything on making the carbonate from the gluconate.
Adding sodium carbonate to the zinc gluconate in solution gives no reaction until it is heated, and then the solution turns milky with a very fine
precipitate (a significant fraction goes straight through the filter paper). But I don't know if that is zinc carbonate or what.
[Edited on 30-3-2008 by Nixie]Nixie - 31-3-2008 at 19:16
Any suggestions?not_important - 31-3-2008 at 21:31
It's likelt that was zinc carbonate. If your gluconate was an OTC medication, it likely has other stuff in it, making your question more difficult to
answer. Often glycine is added to counter the bitter after-taste of the zinc gluconate, and the amino acid can get in the way of good precipitation.
Even without that the gluconate may modify the formation of the carbonate, preventing the formation of dense crystalline forms.
BTW - using sodium carbonate will result in a basic zinc carbonate, the bicarbonate must be used to obtain the normal carbonate ZnCO3; magnesium is
similar.
You're not likely to find anything about making the carbonate from the gluconate, that's a rather expensive starting compound. But the older texts
can gives examples of preparing both the normal and basic carbonates.Nixie - 31-3-2008 at 23:33
So is using the basic carbonate a problem? After all my goal is to I'm convert to citrate by dissolving in a citric acid solution. The reason I used
carbonate instead of bicarbonate was that I figured the chance of a reaction was better with the stronger alkaline.not_important - 31-3-2008 at 23:55
If vulture 's post back up there is correct, you may need to know with decent precision how much zinc you have. The basic carbonates often have a
somewhat variable composition, I don't know if this is true in the case of zinc, which might prevent simple weighting being used to set the amount of
zinc.Nixie - 1-4-2008 at 00:44
If I end up with some excess of carbonate that is fine. I'd have sodium citrate as well as zinc citrate in the end, but I doubt that would affect its
effectiveness.
