My GC system is:column Heysep D 100/120 > TCD > Methanizer > FID.
However I am getting CO and CO2 peak when I inject Air.
So, there is a chance to over quantify of CO in presence of air in sample. Please advice why it is happening and how can I get remedy.
CO is a common constitutent of air. Natural Background is around 0.1ppm but might be 1 - 2 orders higher eg in urban settings (incomplete combustion, traffic etc).
In my case the peak is not very low. It is around 3000-4000 PPM for both CO and CO2.
Try to run 10 PPM each CO & CO2 standard. & then quantify, if your quantification reflects OK then air is polluted.
Have you checked your quantification as Waqar suggested?
Not considering your problem with CO, 3000-4000ppm CO2 seems awfully high for an air sample :-)
This link on chromforum gives a very plausible to an identical question explanation; http://www.chromforum.org/viewtopic.php?f=2&t=29341
I dont have CO standard right now. But I tried with standard mixture of CO CO2 H2. They are giving me very consistent results. I will try with injection port cleaning and catalyst aging. Thank you for all of your informative suggestion.
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