>month, I was running out of glyoxal too quickly. However, Paulchemprof
>suggests trying sodium bicarbonate instead, for a reason I didn't
>understand, but I will....
I think he meant substituting sodium bicarbonate instead of sodium hydroxide
for providing the alkalinity.
Sodium bicarbonate is baking soda (NOT baking powder!), which is a lot less
hazardous than sodium hydroxide (lye). Bicarb will provide a pH of 8 very
easily, as it hydrolyzes in water to sodium hydroxide and carbonic acid (the
solution equivalent of carbon dioxide). It is slightly alkaline, easy to
handle, and easily available. In solution, it is a buffered alkali, and can
be very useful when you need just a wee bit of alkali. Also, it is not as
critical in quantity as sodium hydroxide, where a very small error results
in a large pH change. The only problem is that if you add acid to a solution
containing bicarb you get bubbles of carbon dioxide!
Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net