High CO2 and Methane samples have been problematic on TO15 preconcentration systems due to both the error in volume determination using mass flow controllers that were calibrated for air,  and for the upset to the baseline that results due to the incomplete elimination of the sample matrix before injection.  This is due mostly to the inability of the relatively large adsorbent particles used in packed traps (35/60, 60/80, 80/100 mesh) to completely release the Methane and CO2 prior to desorption into the MS.  During Cryogenic Focusing, any residual Methane will mostly be eliminated, but the remaining CO2 will also be retained in the focusing trap, creating a huge background in GCMS chromatogram. Even systems that use a secondary micro trap based on “packed trap” technology will suffer for excess CO2 release into the GCMS.

Performance Comparison - Volatiles Analysis of Samples with Elevated CO2 & Methane Levels Appletopen  Download 
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Create DateDecember 5, 2018
Last UpdatedDecember 5, 2018