Oligo stability in water at -20 C----pH of water

Peter pxpst2 at unixs.cis.pitt.edu
Wed Aug 12 20:52:12 EST 1998


In article <l03130303b1f7cdd0e8d9@[129.127.90.50]>,
adobrovi at medicine.adelaide.edu.au (alex dobrovic) wrote:

> It doesn't matter what comes out of the MilliQ-the CO2 dissolves in the
> water subsequently and there is nothing you can do about it- you have a
> very weak solution of carbonic acid- but its buffering capacity is
> negligible.

I am not disputing the fact that over time CO2 will dissolve in water but
I do question the time that this will occur.

CO2 must undergo Hydration/Dehydration step in order to form the buffer
component H2CO3. This is the rate limiting step and this is a very slow
process.  The body uses an enzyme called Carbonic Anhydrase(which happens
to be one of the fastest if not the fastest enzymes in the body) to
facilitate this step. The second step is the ionization of H2CO3.  This
rxn is virtually instantaneous.  And since we are talking about disolving
a gas, the surface area of exposure to the gas, the partial pressure of
the gas and the temperature are all that matter.  If I cared greatly about
the quality of the water I would never use it for critical purposes after
it has sat more than 12 hours. 

Peter

-- 
"Don't you eat that yellow snow
            watch out where the Huskies go"    FZ

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