We have a standard GasBench II with 100 microliter loop with
no PreCon connected to a DeltaPlus XL. I have a question about d13C
of DIC. Using 2ml of a KHCO3 standard with a carbon concentration of
50mg/liter I get voltages of about 3000mV and fine results.
My question/problem is that using the cookbook procedure from
Finnigan (a file called DIC.pdf) I get very low voltages (400mV).
The cookbook calls for 0.7ml of seawater. My calculations for
seawater (2millimolar C) concentration are 24mg C /liter. So I am
obviously using much too little compared to my standard.
So, is the problem with the cookbook procedure or with
sensitivity of my GasBench/DeltaPlus? How much seawater do others
use and which loop.
Thanks in advance, Jason
Jason Curtis, Ph.D.
Stable Isotope Mass Spec Lab manager
Department of Geological Sciences
241 Williamson Hall
University of Florida
Gainesville, FL 32611
[log in to unmask], office 352-392-2296
lab 352-392-3344, fax 352-392-9294