Hi Carolina and Gerry,

The main cause for the skyrocketing mass 30 is an oxidation reactor
exposed to air or oxygen when still hot. The first sign of an exhausted
reduction reactor will be smaller peaks and/or shifting d-15 values (the
same are the signs for the oxidation reactor). The best method to check
it, is putting standards into the sequence and comparing their d-15
values. Then you change one reactor after another and check for
improvement to indentify the culprit.

Regards

Jakov

-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On
Behalf Of Gerard Olack
Sent: Freitag, 28. September 2007 23:46
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] 15N enrichment in amino acids

HI Carolina--

Mass 30 will start to skyrocket--NO, mass 30, formed during the initial
combustion doesn't get converted to N2 when the reduction column fails.

It usually co-elutes with the N2 peak (at most, only a few seconds after
it).

take care

gerry

Cabral, Carolina B., M.D. wrote:
> Hi List,
>
> Anyone has a suggestion of how to test if the reduction reactor is 
> working properly? I'm doing 15N enrichment in aminoacids, but I am not

> sure the reduction reactor is working properly.
>
> Thank you very much,
>
>
> Carolina B. Cabral
> Shriners Hospitals
> Research Department
> 51 Blossom st, 4th fl.
> Boston - MA
> 02114 US
> phone: 1-617-371 4932
>
>
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