Isotpic exchange in a carboate system

[karelaorange]

Hi,

 

I'm trying to model isotopic exchange in a carbonate system and I find information for several species of interest is missing, particularly for carbon isotopes. Furthermore, the database says that the reference species for Carbon is "aqueous or gaseous CO2", which I find discomforting considering there should be a fractionation between the two.

 

So my question is, how do I change the reference species for carbon isotopes to CO2(g)? I'm unclear what the reference species currently is, because despite what the introductory database text says, CO2(aq) is listed as the reference species further down in the database.

 

Thanks for your help,

Allison Burnett

[Tom Meuzelaar]

Hi,

 

I'm trying to model isotopic exchange in a carbonate system and I find information for several species of interest is missing, particularly for carbon isotopes. Furthermore, the database says that the reference species for Carbon is "aqueous or gaseous CO2", which I find discomforting considering there should be a fractionation between the two.

 

So my question is, how do I change the reference species for carbon isotopes to CO2(g)? I'm unclear what the reference species currently is, because despite what the introductory database text says, CO2(aq) is listed as the reference species further down in the database.

 

Thanks for your help,

Allison Burnett

 

Hi Alison:

 

The reference species listed in isotope.dat is just a species with a fractionation factor of zero. The other species are listed relative to the composition of the reference species.

 

I hope that helps,

 

Tom Meuzelaar

RockWare, Inc.