There’s another recent update with tips and tricks for the method that may
be useful to folks:

Weigand, M. A., Foriel, J., Barnett, B., Oleynik, S. & Sigman, D. Updates
to instrumentation and protocols for isotopic analysis of nitrate by the
denitrifier method. Rapid Commun. Mass Spectrom. 30, 1365–1383 (2016).

On Mon, Sep 3, 2018 at 10:47 AM, Andrew Schauer <[log in to unmask]>

> Hi Naomi,
> The amount of time your collect N2O in your first trap depends on the flow
> rate while sparging the sample vial. You can check if your sparge time is
> long enough by repeatedly collecting from the same sample vial. You should
> also consider whether or not to bubble. Bubblers place their needle below
> the liquid level so that the carrier gas strips the dissolved N2O from the
> media / sample. Non bubblers leave the needle above the liquid level,
> probably do not gather all of the N2O, and run standards to account for
> that fact.
> As Callum suggested, McIllvin and Casciotti 2011 have some great tips
> (e.g. needle design and septa).
> andy
> On Sun, Sep 2, 2018 at 7:49 PM Naomi Geeraert <[log in to unmask]> wrote:
>> Dear all,
>> We have just set up our Gasbench to do the denitrifier method for nitrate
>> analysis in water. I would like to know from other users of this method how
>> long they keep the LN-traps down. Is there a way to test after how much
>> flushing time all the sample is retrieved? Right now, our method takes 30
>> minutes per sample, but that seems pretty long.
>> Any other advice/mistakes to avoid are also much appreciated.
>> Cheers,
>> Naomi
>> Dr.  Naomi Geeraert
>> Swire Institute of Marine Science
>> The University of Hong Kong
>> Kadoorie Biological Sciences Building
>> Pokfulam Road, Hong Kong, PRC
>> [log in to unmask]
>> ----------------------------------------------------
> --
> Andrew Schauer
> 206.543.6327
> [log in to unmask]
> * <>*

Sebastian Kopf
Assistant Professor
Geomicrobial Physiology Lab <>
University of Colorado Boulder
Department of Geological Sciences
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+1 (303) 735-6207