Chromatography Forum

Hi all, I'm new to this forum and fairly new to working with GC's. I have a Thermo Scientific Trace GC Ultra. It has been down for over a year due to a bad ECD. The ECD arrived and was installed a couple of weeks ago and installed a new lower silver seal (gasket). Powered GC up, turned on oven, base temp and ECD temp and let GC run for a couple of hours. The frequency is showing 271 KHZ. Ran a leak test on the GC and it failed. Ran leak test with the ECD removed and ECD connection capped and shows no leak. Installed another ECD it fails leak test and same frequency. Any ideas of what to try next? Was thinking of installing a second silver seal. The GC operator says the frequency should normally be around 2 KHZ prior to them running a method, is that correct?

It's appearing that the ECD isn't making a good seal inside the GC. Added a second lower seal and second upper seal to no avail.

Are you sure you're running the correct size ferrules?

Yes we have verified that.