Torsten,
A variation on Bill Patterson's suggestion is to introduce a small amount
of saturated HgCl2 into each vessel which you are going to collect your
samples in advance and then allowing them to dry  completely.  This way you
get the Hg and no worry of spilling any crystals.  Of course, if Hg is some
kind of problem...  Sterilization by UV?

Hope life is treating  you and yours well in Tuebingen.

Jim

 >Dear Isogeochemists
>
>We are interested in analyzing DIC from groundwaters by acidification with
>H3PO4. The water samples are commonly poisoned with HgCl2 for this method.
>Would anyone know if  there is an alternative to the HgCl2?
>
>Thanks in advance, greetings
>
>Torsten.
>
>------------------------------------
>Torsten W. Vennemann
>Institute for Geochemistry
>University of Tuebingen
>Wilhelmstr. 56
>72074 Tuebingen
>Germany
>
>Tel: (0)7071 29 74992
>Fax: (0)7071 29 6870
>----------------------------------


Jim Burdett
Cornell Laboratory for Stable Isotope Analysis
125 Boyce Thompson Intitute
Tower Rd.
Ithaca NY  14853

Telephone:  (607)  254-6732 (office), 254-1227 (prep lab), 254-1382 (mass
specs)
FAX:  (607)  254-1382