Dear isogeochemists:

Our lab will be studying changes in the C/N, del13C, and del15N of bulk
organic material from lacustrine and marine sediments.  The analyses will
be performed using a Carlo Erba NA1500 attached to a Delta + by a conflow
device.  Although there are several protocols out there for other types of
sediment analysis, I am unaware of any protocol that we should follow for
sediment acidification.  Because some of the organic fraction is
susceptable to degradation during acidification, it seems important to use
the method that is least harmful to the organic fraction.

I would like some feedback on how other labs are acidifying their sediment
samples to remove carbonate.

Clearly, a way to get around this is to acidify a sample in the tin/silver
boat, the night before it is to be run.  However, which acid is best for
this technique?

Thanks for the input!

Harry Rowe
Geological and Environmental Sciences
Stanford University