The recent posts by William Mark, and Paul Brooks have got me enthusiastic again about pooling resources between labs to address standardization for CNOS and H in particular.
I would really be interested to see a compilation of all the working standards that are being used in the labs, along with what primary isotope reference they were calibrated against.  Perhaps we should devote a special session to the CF-IRMS workshop this year to work up a spreadsheet we could post, and compile as many contributions as we can, making it available to all.  A lot of work, but something that could be very useful.  

William Rugh, Chemist
Integrated Stable Isotope Research Facility
US EPA, NHEERL
Western Ecology Division
200 SW 35th St.
Corvallis, OR 97333
Office phone: (541) 754-4604
Lab phone:     (541) 754-4515