Hi All,

 We are getting ready to measure the nitrogen isotopic values of N2O 
produced via the "Bug Method"  (i.e., Sigman et al. and Casciotti et 
al.).   I am looking into getting a N2O tank from our vendor to use as 
the reference gas.   What is the minimum grade N2O that is required for 
use as the reference gas?  Do I need UHP or can I get away with 
something less expensive? There seems to be a variety of options at a 
great range of cost.

 Thank you,

 Kathy



-- 
Kathryn Venz Curtis, PhD
Stable Isotope Mass Spec Lab Manager, Senior Chemist
Soil and Water Science Department
2169 McCarty-A 
University of Florida
Gainesville, FL  32611-0292             Phone: (352) 392-1951 ext.242