>Dear All:
>
>I found the isotope values of the air nitrogen near our lab fluctuating.
>Sometimes they can be off by 0.5 per mil. Does anybody have the similar
>experiences? Are there any tricks in collecting air nitrogen for standard
>calibration?
>
>Thanks.
>
>Dachun Zhang
>Global Geochemistry Corp.
>6919 Eton Ave.
>Canoga Park, CA 91303


Have you verified (and corrected) the influence of argon on measured 15N
ratio for your IRMS ?

Sincerely



                         -   Andre MARIOTTI   -

           Universite Pierre et Marie Curie - INRA - CNRS
                "Biogeochimie Isotopique" - UMR 7618
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