> Can someone advice me or suggest a reference on how much cabonate
> sample (mollusks) is needed for isotope analysis of N, C, S and O on
> Thermoelectron Delta V plus (Kiel IV).  How about for elemental
> analysis on TC/EA. My samples are pure CaCO3 (mollusk shells). Is
> there a way to calculate the amount of sample needed based on the
> percent of C in the sample? Any reference?

I always tell the students: When you can see it we can measure it.
The sample amount will range somewhere between 200 and 400 mikrogramms
(10-6 gramm), but can be lower in special cases, depending on your
setup.

For a carbonate setup with the gasbench (not Kiel device) you may refer
to:

Spoetl C., and Vennemann T.W., 2003. Continuous-flow IRMS analysis of 
carbonate minerals. Rapid Communications in Mass Spectrometry, V. 17, p.

1004-1006.


> The same question for water samples how much samples do I need for O
> and H isotope analysis on Thermoelectron Delta V plus.

Depends on the device on your massepec. 
Using an TC/EA will need only mikroliters while an equilibration unit
will need a few milliliter.

regards,
Robert



--
Dr. Robert van Geldern
Leibniz Institute for Applied Geosciences (GGA)
S3: Geochronology and Isotopehydrology
Stilleweg 2, 30655 Hannover, Germany
phone: +49-(0)511-643-2313 (office), -2539 (lab)
fax: +49-(0)511-643-3665
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