Paul,

I would suggest that you contact either Cambridge Isotope Labs (CIL) or
Isotec. Both companies seperate and enrich deuterium (primarily for NMR
solvents), however, they may be able to give you insight on where to purchase
a stable source of H/D with a known (and NIST tracable) D delta value.

Best regards,
Mark Lemley
(former Europa Inc and former Analytical Technology Products Inc employee)