Chromatography Forum

Hi
Why am I not able to detect Hydrogen using HaySepC and molecular sieve 5A columns with TCD detector, Helium as carrier gas,
Injection temperature = 200C
TCD Temp = 200C

thanks
Suni

You did not mention the concentration at which you are trying to detect and the amount of gas you are injecting.

There are a lot of reasons why you are not detecting H2.

Detector problems

Leak problems

Injection problems

The low and NEGATIVE response H2 has using He as a carrier on a TCD detector

I hope this will give you enough information to troubleshoot your analysis problem.

Good luck,

Rod

Thanks, Rod.

I have checked the leak,etc..

I tried with 5% Hydrogen in Nitrogen.
The sample flow rate in GC is 15ml/min.

Also using 10 port gas sampling valve.
thanks for the immediate reply....

regards
Suni

You did not state what column you are using. A poor quality column or a poor installation will make H2 difficult to see at only 5% using Helium carrier.

Try using Nitrogen carrier for improved sensitivity.

good luck,

Rod

Two columns - HaySepC and molecular sieve 5A

thanks
Suni