Carbonate devices

Three of the mass spectrometer, two Finnigan MAT 251 and one Finnigan MAT 252 are connected to carbonate devices type "Kiel" or "Bremen", resp.
CO2 produced from carbonates is meassured regarding the 45/44 and 46/44 relation against a standard gas. The standard gas we use comes from a natural table water source and its isotope values are quite near to carbonates of marine origin.
Each carbonate device run 36 samples plus 8 internal standards a day, which gives a total of nearly 30.000 samples per year.
Mainly, foraminifera from deep sea sediments and coral samples are meassured, but the preparation device suits for all other kind of carbonates as well.

FAQs about the carbonate devices:

1.) How much carbonate is needed?
The amount of carbonate needed for a meassurement is 20 to 100 mikrogramm (p.e. 5 specimen of G. ruber)

2.) What is the accuracy of the meassurements?
The long-term standard deviation of our internal standard is < 0.05‰ for delta C-13 and < 0.07‰ for delta O-18

3) Which standards do you use?
We use a Solnhofen Limestone which is calibrated against NBS 19 as internal standard.