Removal of hydrocarbons Carryover on GC

[seamoro]

Does anybody know a purge/cleaning method for removal of carryover of hydrocarbons. I am running liquid hydrocarbons C1-C20 and they remaining on the column or sample lines and im getting carryover/contamination. I would really appreciate your responses. I have a 35 billion dollar project breathing down my neck.

[tkubowicz]

Hello

I'd recommend to narrow it down and check if the problem is with inlet or column.

1. Inlet problem - if some analytes stay in liner you can check: different liner type,inlet temperature, split ratio, pulsed mode - perhaps they can be adjusted and solve problem with carryover. Check visually if liner is dirty after few injections.

2. Column problem - increase final method temperature and leave it for 10 minutes to see if something is coming out - perhaps you need to optimize method a bit.

Note: you can check backflushing option https://www.agilent.com/cs/library/appl ... 8588EN.pdf if you have Agilent GC

Regards

Tomasz Kubowicz

[Peter Apps]

Does anybody know a purge/cleaning method for removal of carryover of hydrocarbons. I am running liquid hydrocarbons C1-C20 and they remaining on the column or sample lines and im getting carryover/contamination. I would really appreciate your responses. I have a 35 billion dollar project breathing down my neck.

If that's your budget you can pay a consultant for advice.

Peter

[MSCHemist]

Clean out your split line? Autosampler vials/other sample prep containers? Another common culprit is the autosampler syringe. I hate the ones with the detachable needles I found compounds hide in the joint between the syringe body and needle. I work with flavor compounds so I can smell and even see them.

[sarakuhl]

What volume are you injecting? With carryover you're either overloading your inlet, column, or both. Do you have fronting or tailing of peaks? Are you using a split injection?

Also consider running a couple blanks btwn samples if nothing else works.