TC:

Try: Hassan, A.A., 1982, Methodologies for extraction of dissolved
inorganic carbon for stable carbon isotope studies: evaluation and
alternatives. U.S.G.S. Water Resources Investigations, 82-6.  Also, there
has been some Isogeochem discussion on this.  Researchers seem to favor
acid-stripping from water over precipitation of carbonate precipitate
(including me), but the latter is commonly used.  See Hassan's study.

Ethan

**********

>Dear Isogeochemers,
>I was wondering if I could obtain a survey of the relative merits of sampling
>ground water for the del-13C of inorganic carbon with either of these two
>
>methods:
>1.  Collecting water poisoned by HgCl2 and then acidified by phosphoric acid in
>the lab.
>2.  Collecting water with BaCl2 or SrCl2 allowing BaCO3 or SrCO3 to form.
>Filtering the precipitate and then acidifying with phosphoric acid in the lab.
>
>Are there any publications that compare the accuracies of each approach?
>Any advice would be greatly appreciated.  Thanks, T.C. Onstott

Department of Geology & Geophysics                  (409) 845-0637
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