Chromatography Forum

We have a Shimadzu GC2010-plus that we are trying to use for measuring N2 (using TCD), N2O (ECD), CH4 and CO2 (FID). We are using N2 as the carrier gas for ECD and FID, and Argon for TCD. We are not using Heluim as carrier as someone might need GC for H2 analysis.

We will be doing some DEA experiments which will potentially result in very high N2O concentrations and possibly too much for ECD to handle. What is the upper limit of N2O concentrations that can be measured using ECD?

Second, can we use TCD for measuring high concentration N2O?. Thermal conductivities of Ar and N2O are 22.6 and 26 (400 KmW/m). Is this too little a difference to see N2O peak on TCD?

Thanks in advance for help

Although the thermal conductivities are similar, if you have large concentrations (%?) then you should still get reasonable peaks. To be honest it'd be easier to use helium carrier and quantify all by TCD. When you need to look for hydrogen, switch to argon carrier gas. That way you get the biggest difference in conductivity for all your applications, that's what we do.

Thanks for your response JR.
I think using He as carrier gas is a good advise considering all pros and cons.

Thanks