Re: Ferric Oxalate

nadeaul@nbnet.nb.ca
Mon, 9 Jan 1995 20:34:20 +0300

> richsul@netcom.com
>
>On Tue, 10 Jan 1995, Shaw, Brian E. wrote:
>
>> Not being a chemist, I find this rather perplexing. I like the idea of
>> doing business with firms like Bostick & Sullivan in business, but is
>there > really a difference between their's and a major chemical house's
>Ferric > Oxalate? Luis and the group, can you provide a little more
..
> My own method which is trade secret
>(not patented) was in some ways discovered by accident. We also add a very
>small quantity of nitric acid to our f.o as a preservative. Nitric acid is
>an oxidizer and evaporates from the emulsion in drying and in the tiny
>quantity used, is reasonably benign to humans and the environment. The
>nitric acid also seems to promote soluablility. Yes EDTA is a good
>additive for enhancing soluability.

A few more tips like this Dick and your f.o. may no longer be a trade secret;-)

>I suspect the problem lies in other companies trying to come up with a
>good way to make it. First off, ferric oxalate is an unstable compound,
>and that's precisely why we use it. A very weak force like light alters
>it. Making unstable compounds is by it's nature a more difficult task.
>Trying to dry a liquid ferric oxalate usually results in the larger
>portion becoming ferrous in the process, thus a problem. Secondly, there
>appears to be no other common use for the stuff, so it's not an issue

Yep. There is no other "common" use as far as I know.

>with the big chemical comapnies. Did, however, sell some to the UCLA
>Dental School for some experiment a few years ago.
>
>I guess things like this are what's keeping the cottage industry movement
>moving.

Indeed

Luis Nadeau

>
>
>Dick Sullivan
>Bostick & Sullivan