On Fri, 13 Mar 1998, Margaret B. Lansing wrote:

> I am having trouble removing carbonates from Lake Michigan coastal
> sediments/sediment trap materials.

Have you done XRD on your samples?  Do they contain dolomite?  Dolomite
will only react slowly with cold HCl.  You may need to heat it to speed up
the reaction, or let it sit much longer. You could also do XRD on the
residue and see if it just contains dolomite, or if another resistant
phase is present.  The sonication step you used might have broken the
grains into finer pieces, thereby increasing the surface area, and
speeding up the dissolution.

Cheers,

Brian

--
    _/     _/_/_/    _/_/  Dr. Brian J. Haskell         Tel:(612) 624-7005
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  _/     _/_/_/   _/       University of Minnesota      Fax:(612) 625-3819
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