When Air gap is 0.2 and the flow rate is 2.1 ml/min then the peak area found 287 by FID but when the air gap is 0 and flow rate is 1.47 ml/min then the area reduced to 141. Where analysis performed by Autosampler.
The airgap is the amount of air that will be behind the sample in your syringe. So if you have 0 airgap in your syringe, it means that the plunger is directly onto the sample. If you have lower area, it is a possibility that there is still some sample in the syringe that has not come out and that is why you are seeing what you are seeing.
Also the fact you have different flow rates make me think your peak shape is not identical which can be a difference in the integration of the peak as well.
I will mark this as assumed answered due to its age, feel free to update us with what you found or post again if this is still an issue.
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