Hi,

I'm looking for oxygen isotope standards for the CO3 component of
biogenic phosphates. I've been running NBS-120c, and getting ~28.2
+/- 0.1 permil (V-SMOW), so it seems reasonably homogeneous (at least
for a couple mg-sized samples). But firstly, I don't know of any
publications that have reported a value for the CO3 component in
phosphate from NBS-120c, so I don't have an independent check on our
value via other labs. And secondly, I'd prefer a lower d18O standard
in addition to NBS-120c. Naturally, we have plenty of carbonate
standards that we also run. But if there's a phosphate standard out
there, I'd like to know about it.

Any thoughts on the value for NBS-120c CO3 component and on
alternative phosphate standards are much appreciated.

Matt

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Dr. Matthew J. Kohn, Assistant Professor
Dept. of Geological Sciences
701 Sumter St., Room EWS 617
University of South Carolina
Columbia, SC 29208
phone: (803)-777-5565   fax:(803)-777-6610
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http://www.geol.sc.edu/kohn/index.htm
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