Dear Karine,
do you think is the same to use a gas (CO2) rather than a solid carbonate having this range of isotopic composition?.

Ciao
Fausto


On Tue, 25 Nov 2003 10:52:57 +0100, Karine Charlier <[log in to unmask]> wrote:

>Dear Isotopists,
>
>I'd like to measure delta13C of organic matter with values between -60
>and -100 per mil.
>Then I'm looking for a solid standard with delta 13C below -60 per mil.
>Do you know  where I can find it ?
>
>Thanks in advance,
>
>Karine