I am facing problem with my GC 7890B, equipped with TCD and FID. On TCD channel I have 2 packed columns;
- Silica Gel
- Molecular Sieve
The GC is being used for the determination of permanent gases (H2, Ar+O2, N2, CH4, CO, & CO2) in gas samples. There is occasional noise in the signal on TCD channel. This noise disturbs the baseline correction modes and especially, when the concentration of components is very low, like we are facing problem for H2 in concentration of around 0.20%. The screenshots of the problem being faced are given below;
Here baseline correction mode is set to 'Advance' and it reconstructs the baseline due to noise in the signal and adds additional area which is not part of the component signal and reads it as signal. The results increase from 0.20% to 0.24%.
Here is the same signal and when the baseline correction mode is set to 'Classic' the baseline reconstructs and ignores the extra area which is due to the noise of the signal it read sample as 0.20%.
This issue of noise in signal creates problem when it appears at the start or at the end of the peak.
The location or RT of the signal noise is not fixed, meaning it can appear anytime on any chromatogram, but it creates significant error in low concentration components.
I want to use the baseline correction of 'advance' as it offers other benefit over the other one (classical).
This noise is visible only when you magnify the signal and error is indicated by the higher result, e.., 0.24% as in routine it is 0.20%
What are the possible ways to overcome this problem?