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TCD not detecting anything

Discussions about GC and other "gas phase" separation techniques.

3 posts Page 1 of 1
Hi,
I am looking for help on a mystery. I have a Shimadzu GC-17A, single injection port with TCD detector. It is used mainly for in process material, our feed material contains salts so I use inj liners with wool to trap some of the gunk and swap them out frequently. I noticed the peaks were starting to come out later so I replaced the liner, trimmed the column on the injection side and replaced the septum. But now the TCD is not detecting ANY peaks. I unhooked the column from the detector to check for flow through the column and that appears normal, trimmed that end of the column while it was unhooked just in case. But there was no change, still no peaks. I only do manual injections so I can see the syringe is working normally. I do get some noise and the baseline increases normally with the temp program then gets wavy on cooldown (which is a little unusual for our GC). I did the zero adjustment and slope test which seemed normal (200). The unit is not detecting any leaks and the flow / pressure are staying on program. The column is only a month old, the one we replaced (same type and length - RTX-5 wide bore 15m) worked well for nearly a year. Not sure what I can try next.

The retention times of the peaks growing larger suggests a leak in the system that was increasing. Did you measure the flow coming out the column to verify the flow at the column outlet is correct?

Contact Shimadzu technical support using the Shimadzu toll free number to see if they have specific troubleshooting tips for this instrument.

Thank you for the response. I came in this morning and the GC appears to be working normally, looks like it just needed to be left alone for a few hours.
3 posts Page 1 of 1

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