How to know TCD failure?

[E11022]

I am using Yokogawa Series 1000 Mark 1 GC to analyze Paraxylene.
The Chromatogram that i got lately seems to be very weird.
The baseline drop from beginning for certain time, then it goes up then only peak appearing.

I had replaced all the columns and even TCD for the GC. All the carrier flow had been checked and doing good.
How to know a TCD is working fine? Any way to check?


Thank you.

Alice

[chromatographer1]

Pray tell, were you, are you programing your oven temperature?

Test the TCD by doing an

Isothermal run

Inject air.

single peak with no tailing should be result.

best wishes,

Rod

[E11022]

i fix my oven temp to 80 degree Celcius (Factory setting).
Tried checking baseline, Baseline okay, no noise/interruption.

[antonk]

maybe your injection system (syringe or valve) grab some air or water vapour which significantly change thermal conductivity of gas in your analytical channel.
Try to inject something inert at lower volume. Air, another gas (e.g. nitrogen in helium carrier).

[zahid]

You can check the resistance of detector