Definitely, TCD are sensitive towards permanent gases and can be used well
Hello Bikash,
yes. Unfortunately molecular sieve 5A is very polar, so you will have problems with elution of CO2. It is possible, but you need to heat up the oven to about 250 deg. C. If you perform a separation of a mixture of permanent gases, start at 40-50 deg. C. After a few minutes ramp to 250 deg.C. Second problem is a so-called W-shape of the peak in case of nitrogen as a carrier gas.
Better solution would be to use helium (or hydrogen) as a carrier gas and porapak Q (or carbon molecular sieve) as stationary phase.
best regards,
G.
Thanks Dr.Grzegorz Boczkaj . Can you please explain about the W shape of the peak when nitrogen is used as a carrier gas.
Hello,
check this topic:https://www.researchgate.net/post/What_can_I_do_to_enhance_the_shape_of_a_CO2_peak_GC-TCD
the attached chromatogram presents this phenomenon - the last peak (I think) is for CO2.
Remember that depending on your carrier/reference gas and polarisation of the detector some peaks can be positive and some negative. Changing the carrier/reference gas (they must be always the same) you can "tune" the sensitivity of your method for specific analyte.
regards,
G
Thanks Dr.Grzegorz for the valuable answer. As you suggested we can get positive and negative peak ( inverted peak), is it possible that we may get a positive peak for H2, O2 and still get a negative peak for CO2 while using N2 as a carrier gas.