As everybody, more than ten years ago, I wanted to found a tank of hydrogen
to use it as a working standard. What I did is that during several months I
took aliquot of the new bottles of hydrogen delivered on the campus (with
the authorisation of the Air liquid producer) each week. If most of the
time the value was rather low (<-300”), finally I found several bottles
(the same day) close to -100” (I tooks two with 80” differences), good as
working standards. Hydrogen fractionate during production and you just have
to wait to be at the right place in the isotopic evolution....
I hope that it will helps.
Laboratoire de Geochimie des Isotopes Stables
Universite de Paris 7 denis Diderot
et Institut de Physique du globe de Paris
2 Place Jussieu
75 251 PARIS CEDX 05, FRANCE