Dear Rob,
Recently, I have started a calibration of two lab standards for 
phosphate d18O analyzes. I have preliminary values for both:
Trisilver orthophosphate (Ag3PO4, SIGMA ALDRICH CHEMIE GmbH Nr. 33,738-2)
Synthetic hydroxyapatite (Ca5(PO4)3OH, MERCK KGaA Nr. 102 196)

If you like, I can send you small amount of each.


best regards

Greg

-------------------------------------------------------------
Dr Grzegorz Skrzypek, Research Assistant Professor

West Australian Biogeochemistry Centre
John de Laeter Centre of Mass Spectrometry
School of Plant Biology, The University of Western Australia
35 Stirling Highway (MO90), Crawley WA 6009, Australia

Phone +61 8 6488 4584, Fax +61 8 64887925
email: [log in to unmask] http://www.bukibuki.eu




Rob Posey wrote:
> Dear Isogeochem users, 
>
> I am a first year PhD student whose project involves the forensic
> provenancing of human remains. As part of my research I am going to be
> analysing the oxygen isotope ratio of phosphate in human bone samples based
> on the method of O'Neil (1994) and Stephan(2000). In order to validate my
> method i require a phosphate standard or bone sample with a known
> d18O(VSMOW) value. Would anyone studying in this field be able to supply me
> with a small amount of standard for this purpose. 
>
> Many thanks, 
>
> Rob Posey
>
> University of East Anglia
>
>