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Hi,

Technically it probably works, but sensitivity decreases since thermal conductivity in TC detector is dependent on the difference between gas masses: difference between helium (4 g/mol) and SO2 (64 g/mol) masses is much bigger than between N2 (28 g/mol) and SO2, but might be still enough, if there is lots of S in samples.
Furthermore, as an example TCD in GC:s can be used to measure hydrogen (2 g/mol) by using N2 as carrier gas, then helium is not ok because too small mass difference.

Hannu Nykänen

University Researcher
University of Eastern Finland, Kuopio

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“New” article about peat carbon stable isotopes: https://doi.org/10.1080/10256016.2018.1523158
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From: Stable Isotope Geochemistry <[log in to unmask]> On Behalf Of Jason Curtis
Sent: keskiviikko 3. heinäkuuta 2019 22.00
To: [log in to unmask]
Subject: [ISOGEOCHEM] Helium saving question - EA for percent S

Has anyone ever tried using nitrogen as the carrier gas in an elemental analyzer when measuring percent S?  Not isotopes or %C and %N.  I don’t see an issue except the baseline would be very high.  I also don’t see how the thermoconductivity detector (TCD) would mind.

If no one warns me against it, I will try it on a Carlo Erba NA1500.  I’ll use UHP N2 for the carrier, reference, and the autosampler purge gases.  And just adjust the baseline down.  If it works (or does not work) I will report back.

Thanks in advance for any advice,
Jason

Jason Curtis, Ph.D.
Stable Isotope Mass Spec Lab manager
Senior Associate-In Geochemistry
Department of Geological Sciences
University of Florida
Gainesville, FL 32611
+1-352-275-8642