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Carrier gas selection for TCD analysis
Posted: Fri Dec 30, 2011 5:22 pm
by AGY2403
I want to know whether Hydrogen or Nitrogen can be used instead of Helium while using TCD detector?
Second thing, how to get TCD Detector conditioned in lesser time?
Re: Carrier gas selection for TCD analysis
Posted: Fri Dec 30, 2011 10:16 pm
by chromatographer1
Yes they can be used. Usually there is a setting to change with the electronics if N2 is used.
Hydrogen can damage metal components of a TCD with long term use.
The TCD does not require 'conditioning' but the column attached to it may.
Use a faster flow rate and a hotter oven to condition a column more quickly.
best wishes,
Rod
Re: Carrier gas selection for TCD analysis
Posted: Sat Dec 31, 2011 5:14 pm
by AGY2403
Thank Rod, I have tried this but the baseline was not stable lots of noise and spike observed.
Thus I want know how to tackle the baseline problem?
Re: Carrier gas selection for TCD analysis
Posted: Tue Jan 03, 2012 10:49 am
by Johnny Rod
I think you want to know how to achieve a stable baseline from the TCD in the shortest time. It takes a while to stabilise as it needs to heat up or cool down and equilibrate, ideally you should be monitoring the baseline during this period, which can be a few hours. If your standby method conditions are close to your analysis conditions, the time needed will be shorter.
Re: Carrier gas selection for TCD analysis
Posted: Tue Jan 03, 2012 10:56 am
by chromatographer1
Johnny's comment is good. You can turn off the electronics of your TCD and leave the detector at temperature as long as you keep carrier gas flowing. Then it should only be a very short time before the electronics and thermister/hot wire are equilibrated.
best wishes,
Rod