Page 1 of 1

Hydrocarbon contamination

Posted: Thu Oct 18, 2007 3:43 pm
by athena
I have been having a problem with hydrocarbon contamination(approximately 9 x 10e6 intensity) on my split/splitless injector, but do not see the hydrocarbon contamination when I switch to my PTV injector. Both injectors are being ran splitless. Both injectors are supplied by the same carrier gas (He) which runs through an SGT triple filter and use the same autosampler. I am using a Thermo Trace GC with a DSQ MS.

The troubleshooting I have tried so far: All pieces of the injection port have been sonicated in chloroform. The injection port (minus the liner) was baked out at 400 °C for 4 hours. The inlet liner was replaced. The autosampler syringe was cleaned with chloroform.

There is an in-line filter (not sure what type) on the carrier gas line that was installed by our Thermo service rep. We suspect the filter, but have no way to prove it.

Has anyone else had this problem? Does anyone have any sugesstions?

Posted: Thu Oct 18, 2007 6:04 pm
by chromatographer1
Can't prove it?

Why can't you remove the inline filter?

Won't that show if it is contributing to your hydrocarbon contamination.

It may take a while for the lines to flush clean.

Something to try.

best wishes,

Rod

Posted: Fri Oct 19, 2007 11:28 am
by Peter Apps
Try changing the septum.

Peter