Greg

For our mass spectrometer running standard we use cylinder N2 (Air Products
Ultra-pure carrier grade).

We run this tank or cylinder gas against an atmospheric nitrogen standard,
prepared on a glass prep line.

For our QA/QC standards we use reagent grade KNO3 and (NH4)2SO4.

Other standards can be obtained from IAEA , Vienna, Austria, or from NIST,
USA.

G. Martin