Hello Marilyn,

I ordered NBS-18 and 19 from IAEA a couple of years
ago and I think it is still possible.  You should find
information at:

http://www-naweb.iaea.org/naml/aqcsmaterials.asp

Also, the stable isotope lab at Centre GEOTOP has a
CaCO3 standard called UQ6a (d13C=2.25 VPDB and
d18O=-1.40 VPDB).  I can send some to you if you'd
like.

Take care,
Jennifer

--- Marilyn Fogel <[log in to unmask]> wrote:

> I may be missing something, but I am having trouble
> finding and  
> purchasing isotope standard materials, particularly
> for carbonates.
> 
> NBS-18 and 19 are no longer available from NIST. The
> N-3 nitrate  
> standard is "backordered". I have found a company
> Iso-Analytical in  
> england that will send over a carbonate reference
> material. We've  
> tried some of their mineral oil and alanine for C
> and N--seem like  
> good references.
> 
> I would like to have a second carbonate (calcite)
> standard. Any  
> suggestions?
> 
> Marilyn
> 
> PS Will accept packets of small white powders (with
> isotopic  
> compositions) if you have them available.
> 
> 
> Dr. Marilyn L. Fogel
> Geophysical Laboratory
> Carnegie Institution of Washington
> 5251 Broad Branch Rd., NW
> Washington, DC 20015
> Phone (202) 478-8981
> Main office (202) 478-8900
> FAX (202) 478-8901
> Website: http://fogel.gl.ciw.edu/
> 
> 


Jennifer Lynn McKay
Centre GEOTOP
University of Quebec at Montreal
CP 8888, succursale Centre-Ville
Montreal, Quebec, Canada
H3C 3P8

514-987-4080 (GEOTOP office)
514-987-3000 ext. 1718 (office)
514-987-3000 ext. 7028 (lab)
514-987-3635 (fax)


      Ask a question on any topic and get answers from real people. Go to Yahoo! Answers and share what you know at http://ca.answers.yahoo.com