German

I've used charcoal for N2 trapping for several years. Initially activated
granular charcoal of Merck (product no. 9624), and now granular
vegetable charcoal from Prolabo (prod. no. 22631.293). Activation is
carried out at up to 400 C under vacuum.

There's a lot of mythology about which charcoal is best. The Prolabo
material was given to me by Tom Preston (Scottish Universities Research
Reactor Centre [log in to unmask]), and I think it's supposed to be
derived from cocoa beans picked by dusky virgins under a full moon, or
whatever. It may be that any material will do.

Tim Heaton

NERC Isotope Geosciences Laboratory
British Geological Survey
Keyworth, Nottingham NG12 5GG

Tel. +44(0)115 936 3401
Fax +44(0)115 936 3302
E-mail: [log in to unmask]


, and it may be that any product is OK.