Chromatography Forum

Hi,

I have a GC/MS FID system. The solvent delay set at 1.30 mins on my MS. The data that is saved starts at 1.389 which is after the methanol peak has nearly finished eluting. The solvent delay is still set at 1.30 but nothing is being save until 1.389. I can see the peak being detected when it's eluting on the live view. If this issue was due to the solvent delay parameters it should only be affecting the MS data and not the FID, but both look similar. I am wondering if anyone has had this problem and what can I do to fix it?

Thanks!

Due to both detectors being destructive, I can only assume you split the injection, either at the inlet or in the oven? The final elution times of the solvent peak may differ slightly. Also, the electronics does have a lag, where the setpoint of a delay and the actual data collection start will differ, but yours is different by +5 seconds, a lot longer than it takes for a filament to become active at the end of the solvent delay. Does the software for the FID have a data collection start time, and is it set the same?