I use Labco caps on borosilicate vials from Fisher with round
bottoms.  Would this help?

>Bernd/Simon,
>
>There are rumors that viton septa work for this purpose, but I'd like to
>see it confirmed.
>
>The material the labco exetainers come from is incredible -- we get
>absolutely no change in 13C or 18O after many many hours of contact with
>the septa.  I wish we knew what that material was!  The ideal thing would
>be to convince Labco to make conical vials or find vials that fit Labco
>caps.
--


********************************
Steve Nelson
Dept. of Geology
S389 ESC
Brigham Young University
Provo. Utah  84602

voice:    1-801-378-8688
lab:      1-801-378-5124
FAX:      1-801-378-8143

CARPE CARP:  seize the fish
********************************