Re: glyoxal testing anyone?

On Sat, 28 Aug 2004, Christina Z. Anderson wrote:

> Thanks Judy, Marek, Mark, et al,
> Will add thicker gelatin, water choice, dif amounts of glyoxal, and
> will put them all in Mark Nelson's bed, not closet, for him to sleep on for

Chris, The thought floated into my mind today (when I was supposedly
thinking about something else), that the main variable in this operation
may not be the air, the rinse, the light, or dark, etc., but the pH of the
paper and/or of the water.

Since I found that an alkali turned the glyoxal orange even in relatively
small amounts, and that that stained the paper orange, and since many
papers are *buffered* in varying degrees, it could be the buffering (the
particular buffering agent and or the level of buffering) that had this
as a residual effect.

I'll mention again that I've kept paper in all kinds of incorrect
unsanitary conditions and only had rare or peripheral yellowing (although
one of my students had noticeable yellowing on paper stored in a wooden
drawer).

So it occurs to me that (happy to give YOU more work) it might be useful
to test two papers. one of higher (buffered) pH, one more or less acid.

Which brings you/us to the isssue of measuring the pH of paper. I have a
pH pen from Light Impressions which gives a crude measure, which may or
may not be calibrated enough to be definitive in this case. No use asking
the manufacturer of the paper, since experience says that (a) they are
very wont to lie and (b) they don't have a clue anyway.

Which brings us to what I'been told is the standard way to measure paper
pH -- grinding the paper up and testing its efflent, or something along
those lines -- but didn't you say that's what great universities are for?

best,

Judy
Received on Sun Aug 29 19:28:10 2004