Dear friends of isotopes: Does somebody out there tell me how to obtain so-called NGS standard gases, which contain methane and some light hydrocarbons with known isotopic compositions? Thank you for any information from you in advance. Sincerely, Nori Tanaka ------------------- Noriyuki Tanaka Laboratory of Marine and Atmospheric Geochemistry(MAG) Graduate School of Environmental Earth Science Hokkaido University, Sapporo, 060 Japan tel 011-706-2370 fax 011-726-6234 Email [log in to unmask]