Chromatography Forum

I am using Thermo ULTRA GC with PTV injector with sintered glass liner in splitless mode. My endrin breakdown is way over 20% after the injector / column maintenance. I am using 5m 0.32mm IP guard column connected to analytical column with SGE micro-connector (stainless steel), the column is DB-17MS, 30 x 0.25 x 0.25, the PTV is used in splitless mode 35 - 275 deg C @ 8 dec C/min. The instrument is about 4 years old. Can someone give me suggestions on how to remedy this problem?
Thank you.
Ivo

Hi
I would recommend to take a look at a series of blog-posts done by my colleague Jack Cochran. He and Scott Grossman have done a lot of work on this topic. We use this component to test liner, seals and columns inertnes.

http://blog.restek.com/?s=endrin+breakd ... ton=Search

regards
jaap

Has this instrument ever given acceptable break down numbers? If yes have you done any injector maintenance in 4 years ( other than liner and septa changes)? If no you may want to consider either cleaning or replacing the injection port.
I use an Agilent 6890 and need to clean my injector every once in a while ( when column clip and liner change have no affect).

Thank you for your response. I solvent cleaned the PTV, replace the liner and the guard column. It helped little bit, to <10%. I also noticed that the breakdown is different when the standard is in different solvents, it was higher in hexane, much lower in acetone.
I will be in touch with Thermo troubleshooting team if it still lingers above 10% after all that maintenance.

You will not get endrin through sintered glass. You'll need a different liner. Jack Cochran's work is stunningly good - I highly recommend it.

What liner would you recommend? I have had good experience with sintered glass liners before. Carbofrit?