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