Hi Yanhua,

You need to do the peak jump between C and N analyses (the technical manual should explain how to do this).  Also, you need to purchase a dilutor to dilute the CO2.  The reason is that normally samples have much more C than N. If you don't do sothe IRMS will be saturated with C signals.  Alternative way is to do them separately if you don't have grant to buy the dilutor right now.

River He

--- On Fri, 11/6/09, Yanhua Feng <[log in to unmask]> wrote:

> From: Yanhua Feng <[log in to unmask]>
> Subject: [ISOGEOCHEM] IsoPrime EA-IRMS N2 measurement
> To: [log in to unmask]
> Received: Friday, November 6, 2009, 1:13 PM
> Dear all,
>     We have an IsoPrime isotope ratio mass
> spectrometer. an EuroVector 3024 
> elemental analyzer is hooked up to it. the EA is configured
> for Carbon &amp; 
> Nitrogen analysis. the software is MassLynx 4.0i.
>     Carbon analysis for percentage and delta 13C
> is our routine. 
>     We never done Nirtogen before.
>     I am looking for a procedure for measuring C
> & N in one or separate 
> analysis, I am hesitated about how to modify " EA NC run "
> or "EA NC diluter" 
> method, cycle the magnet, when to open RN and when to open
> RG, how much 
> pressure set for RN. 
>     any suggestion or clue would be appreciated.
> 
> 
> Yanhua Feng
> 
> Plant & Environmental Sciences
> New Mexico State University
> Las Cruces, NM 88003
> 


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