GC 8890 - baseline dropping and rising at the same retention time

Does this happen with no injection - either remove the syringe from the ALS or set it up to acquire a manual run and just push Start on the GC?

What solvent are you injecting?

Please give all the injection port and column flow parameters, too. 

Hello Paulsalverda,

This happened with no injection/instrument injection, and I did not inject any solvent with this blank injection.

I did use ethanol before.

I used cyclo type liner inlet.

Split flow ratio: 200:1

flow rate: 399.94 ml/min

Thank you,

ChauDang

I looked at your plot again. That little bounce is barely 0.01pA -- so very tiny!  This is down in the lowest possible signals that can be measured with an FID and honestly should not matter as your smallest peaks of interest should be at least 50x to 100x larger than this baseline disturbance.

Can you share the chromatograms of your lowest and highest level standards?  Does this bump show in those chromatograms? 

I looked at your plot again. That little bounce is barely 0.01pA -- so very tiny!  This is down in the lowest possible signals that can be measured with an FID and honestly should not matter as your smallest peaks of interest should be at least 50x to 100x larger than this baseline disturbance.

Can you share the chromatograms of your lowest and highest level standards?  Does this bump show in those chromatograms? 

Thank you Paulsalverda,

I tried to run a standard and it did not show the bump on my chromatograms. Thank you for verifying this information for me! I was worrying too much about this!