Dear all,
I know about the problem described by Patric Dauby. The only way to
avoid the reaction of water with Zn in Pyrex tube is to reduce hydrogen
as soon as possible after the freezing of water in ampoule with Zn.
When I prepare hydrogen for D/H analysis I put Pyrex tubes with water
and Zn into the furnace directly after  closing  them in the preparation

line.
Regards

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Anita Weber-Weller
Laboratory of Isotope Geology and Biogeochemistry
Institute of Geological Sciences, University of Wroclaw,
Cybulskiego 30, 50-205 Wroclaw, POLAND
tel. +48 71 402-496
e-mail: [log in to unmask]
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