Chromatography Forum

I am currently trying to help a sister lab in my company set up a new GC that they accquired from elsewhere in our organisation. They want to determine the phenol content of samples and if possible, the levels of Methanol and IPA as well. The old GC that has died was FID and they had hoped that a method could be set up on the TCD-GC that they accquired.

I am not sure if this is possible so I thought I would ask.

Any help on this matter would be greatly appreciated.

Thermal conductivity is just like any other detector. You should be able to do it - although your detection limits probably won't be what you get with a flame. If you're looking for residual amounts of the components you listed, it could be difficult. Tough to beat the flame for low detection limits and ease of use.

Good luck. It's certainly worth a shot. My $0.02.

Thermal conductivity is just like any other detector. You should be able to do it - although your detection limits probably won't be what you get with a flame.

The detection issues were what was worrying me, I guess it is something we should at least try.....

Thanks for your input.

lwt77,

Method ASTM D-3606 uses a TCD to measure benzene in gasoline. I have run the older 5890 with a 2 uL injection (packed column) down to around 0.1 vol % or so when looking for "low" levels of benzene. If you need to go much lower, you might consider an FID or AID for this application. Unless really, really low the only advantage of AID over FID is not having hydrogen in the lab. If you already have hydrogen, it's a wash.

Best regards,

AICMM

If the two GCs are the same model or similar, maybe the FID from one could be installed into the working one. On Agilent, that would be plumbing, FID, circuit board, and similar.

Moving the FID is defintely worth looking into. With the some of the newere model instruments it is a matter of unplug from one and plug into the other - OK there are a few screws also...

Thermal conductivity is just like any other detector. You should be able to do it - although your detection limits probably won't be what you get with a flame.

The detection issues were what was worrying me, I guess it is something we should at least try.....

Thanks for your input.

What detection limits are you hoping for? What sort of injector is it equiped with? I agree,if they are both 6890s for instance,take the detector you need.

Actually,if they are both 6890s,the next question is,what went wrong with one that you say it "Died".