Re: Gum print formaline

From: Katharine Thayer ^lt;kthayer@pacifier.com>
Date: 02/03/05-03:34:02 AM Z
Message-id: <4201F001.61F4@pacifier.com>

Just for the heck of it, I calculated the relevant percentages. If I
figured right (I'm better at statistics than I am at simple arithmetic)
it comes out thus:

25 ml of 40% glyoxal in a liter is 1%

15 ml of 40% glyoxal in a liter is .6%

6 ml of 2.5% glutaraldehyde in a liter is .015 %

The smaller amount of glyoxal (.6%) is 40X the concentration of the
glutaraldehyde concentration Chris recommends. My question continues to
be, could someone show me some stoichiometry to explain why that much
more glyoxal is required to harden the gelatin?

If I had time, I would run some tests with pigment in the gelatin at
different glyoxal concentrations and see at what concentration the
gelatin is hardened to the point it can't be removed with hot water, but
unfortunately I don't.

It's interesting that Kees reports no grittiness in his glyoxal-hardened
gelatin.

Katharine
Received on Thu Feb 3 11:30:34 2005

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