Dave,
You don't need the chromium trioxide or the hydrogen peroxide, but its best
if you have dry acid. You'll be pumping tons of water out of your system.
Enough to influence the measurements on the evolved carbon dioxide.
Bite the bullet & make the dry acid. Either by addition of phosphorous
pentoxide or vacuum cooking.
Cheers,
Bob

>Another phosphoric acid question- Please respond if you have an answer!
>We are running a machine to measure calcium carbonate by the pressure
>evolved-no mass spec! :-(
>(reacting samples under vaccum in a common acid bath at 80 deg C)
>
>Although using the dry acid has been suggested, is there a reason we can't
>just use off the shelf 85% ortho phosphoric acid, avoiding the hydrogen
>peroxide, chromium trioxide altogether?
>thanks,
>dave anderson
>
>______________________________________________________________________
>David M. Anderson (Phone: 303-497-6237, FAX: 497-6513)
>NOAA Paleoclimatology Program, 325 Broadway Code E/GC, Boulder, CO 80303-3328
>______________________________________________________________________

-----------------------------------------------------
Bob Fifer
Brown University                E-mail: [log in to unmask]
Providence, RI 02912            Geological Sciences

Phone:  401-863-1698
Fax:    401-863-2058