Hi Darren,
I don't know if the BCR-1 has been exhausted, but we use it in our lab for
calibrating our Rb/Sr- and Sm/Nd-spike solutions and as a control standard
in every batch of samples we analyse. Cassidy and Chauvel have reported in
Chemical Geology, 74(1989)189-200 a value for 87Sr/86Sr of 0.705003 +/-
0.000010 which is about the same as we get.

Helge


Helge Stray
Institute for Energy Technology
P.O.Box 40
N-2007 Kjeller
Norway