Cleaning split vent?

[Tasneem12]

Hi All,

I recently dirty soil samples through PyGCMS. Py unit is working fine after cleaning up the seals but GC pressure is failing to hold. The column is new, I changed the ferrules, changed the septum and split liner. It is still failing, I am wondering if I need to clean the split vent, I haven't cleaned it in 2 years. I am looking for instructional videos to clean it but I cannt find it. If you have suggestuions/recommendations please share. The unit is a shimadzu QP 2020NX with a GC-2030.

Thank you
Tasneem

[Consumer Products Guy]

I never worked with Shimadzu, just HP/Agilent; and on a couple of our units I had to clean out the split vent line. On at least one I increased the stainless steel tubing diameter.

I'd call Shimadzu and request instructions on how to do this.

[Tasneem12]

Thank you, I have reached out to Shimadzu and waiting to hear back from them.

Is it a very regular procedure to clean vent line? Or is it supposed to be taken care of by the split filter? I am wondering if my problem is elsewhere.

So the issue we are having is GC is failing to hold higher pressure. I am thinking there is probably a block somewhere.

Changed the ferrules, septum, liner and cut a few cm of the column nothing solved the problem.

The error i mostly get is "Car1 AFC control irregularity" and one time I also got "CAR1 AFC valve not closed"
Please let me know if you have any suggestions.

Tasneem

[Peter Apps]

Dirt in the split vent cannot cause a pressure failure, there is a leak somewhere. Do you have a leak seeker?

[Tasneem12]

Actually it doesn't fail to hold a certain pressure, it holds pressure fine, its the split flow that is having issues. Split flow higher than 30 mL/min is becoming impossible to run. It lets me run split 20 or 10. But if I try split 50 and above it fails to hold the split flow.

I do have a leak seeker and I couldn't find anything.