Chromatography Forum

Some of you has experience measuring Cl and Hcl with capillary Q-Bond type column and PDHID detector?

I try to measure 20ppm chlorine and 20ppm hydrogen chlorine without success.

Carrier gas is Helium UHP. I expected to have a peak somewhere after water peak but can't see it.

Some ideas

Are you injecting aqueous solutions of HCl in water? If yes, you're not going to ever see anything. These analytes are not amenable to GC analysis. Ion chromatography (look for cloride) or an acid/base titration is the way you want to go.

You probably have enough active sites with the glue as well as the residual starting monomers that it will take you a long time to deactivate the column enough to elute these low levels of Cl2 and HCl. If you have moisture in the matrix that is even more difficult to achieve as both analytes will react with the water.

And the column you are using is not the best for the analytes you are measuring, but I think you have already discovered this on your own.

best wishes,

Rod

sample gas is 20ppm cl2 and 20ppm hcl in a balance of helium.
It is a aluminium certified Linde cylinder and I have silconert 2000 tubing that bring gas to GC valve which is all silconert 2000 threated.
I assume there is no water or lower than 10ppm water in sample. My carrier gas is UHP, then I assume my column is very dry as well.

Which columns could offer better performances.

Thanks