Missing compounds using air bags and sample loops

[Yama001]

I assume there is a heated transfer line from the heated valve box to the inlet.

The high pressure noted in the OP could be an issue? If the valve setup is leaking somewhere you may see a poor transfer to the column?

[chromatographer1]

Good points to make Yama001.

There are more but so many blogs. So little time. So little information.

best wishes,

Rod