Hi David
The PreCon is a prep device, like an EA or a GC, whereas the GasBench is an interface.  The PreCon needs an interface which can be the GC-C or similar including the GB.  The original idea behind the PreCon is to analyse 13C of CH4 or N2O from 100ml flasks of air.  The PreCon has a combustion furnace that is used to convert atm CH4 to CO2 and it is turned off for N2O cryofocussing and analysis. Many labs use the PreCon's traps to do other types of sampling when they don't have a GB with traps (e.g Breath analysis). 

The prep device that is typically sold with a GB is the multi-sample heated bloc with an autosampler to do water (D, 18O), carbonates (13C, 18O) etc.

The double traps will allow you to do things like cryofocussing small carbonate samples, atm CO2 (depending on precision needed, e.g. Growth chamber monitoring), Bacterial N2O cryofocussing, Breath test for H. Pylori, etc.


If you have more questions, feel free to call.

Hope this helps
Gilles  

Gilles St-Jean
Chercheur / Research Scientist
Université d'Ottawa / University of Ottawa
Sciences de la Terre / Earth Sciences
140 Louis Pasteur, Ottawa, Ontario, Canada K1N 6N5
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-----Message d'origine-----
De : Stable Isotope Geochemistry [mailto:[log in to unmask]] De la part de David Denhaan
Envoyé : 17 avril 2007 15:50
À : [log in to unmask]
Objet : [ISOGEOCHEM] Precon and gasbench II

Dear List,

We are looking at interfaces for a Delta V that is going to be installed in our lab. We have an EA  and are looking at getting a Gasbench II for gas samples.  We are a bit confused about the use of the Precon device and the Gasbench II.  Do you need both?  It seems like if you ordered the Gasbench II with two liquid nitrogen traps the Precon would not be necessary.  Is this correct?

Thanks,

David DenHaan