Dear Frank and listmembers,

I use Indiana zinc, too. You can see a little contribution to the
preparation problems in Demeny (1995, Chem. Geol., 121,
19-25.) where I discuss the effect of zinc-hydrogen reaction after
water conversion. This was later confirmed with other batches, see
a last years' posting by Torsten Vennemann to isogeochem on this
matter. When I use this zinc I always take a small part from the
large batch and I store the remaining zinc under vacuum. Usually
the last portion of the large zinc batch is full of zinc powder and it
gives very bad results. I observed this effect like your case, from
one day to another, then I discarded this remaining zinc. I can
imagine a difference in handling that one takes only the nices zinc
grains, while someone else takes care only about weighing the
given amount. Such things tipically occurs in our lab. I hope this
helps.
Cheers,
Attila

Dr. Attila Demeny
Laboratory for Geochemical Research
Hungarian Academy of Sciences
Budapest, Budaorsi ut 45, H-1112, Hungary
tel/fax: 36-1-319-3145
e-mail: [log in to unmask]