An oxidative EA environment can quantitatively form N2 from ammonium
sulfate, but not from nitrates. Nitrates need to be reduced to N2. Some
time ago it was suggested to pre-mix some sucrose with the nitrate
reference material to solve the problem, namely the sucrose reduces the
nitrate to N2. Unfortunately I forgot the reference. It had something to
do with a 'sweet solution'.
On 3/6/2015 3:03 PM, Jennifer McKay wrote:
> Hi Everyone,
> Has anyone noticed "odd" behaviour of IAEA-N3 (potassium nitrate) when
> running it through the EA-IRMS? I have only used it a couple of times
> and in both instances the standards at the end of the run were "off".
> In the first instance the IAEA-N3 values a the end of the run were a
> tad heavier than those at the start and in the other instance (after
> sitting in the autosampler for >24 hr) much lighter. No problems
> (i.e., strange drifts) for the USGS 40 in the same runs.
> Before starting to run all sorts of tests to figure out what's going
> on I thought I'd ask.
> Bye for now,
Arndt Schimmelmann, Ph.D. | Senior Scientist
Indiana University | Department of Geological Sciences
1001 East 10th Street | Bloomington, IN 47405-1405 | USA
Ph (812) 855-7645 | Home (812) 339-3708 | FAX (812) 855-7899
e-mail: [log in to unmask]