Measuring hydrogen with HayeSep Q (80/100) column

[YDY]

Hi,
I am trying to measure hydrogen with a TCD using Hayesep Q (80/100) column with N2 as the carrier gas. What should be the parameters in the method, e.g. oven temperature, detector temperature, inlet temperature. Thanks

[chromatographer1]

Long column over short. I would prefer at least a 4m column 2.1mm ID (9m 1mm ID would be better).

35C or cooler if possible oven temperature

20cc/min or lower if possible.

As small as possible injection volume. This affects LOD however.

best wishes,

Rod

[chromatographer1]

As long as you have separation from neon and oxygen you will have no problems. Just check that helium is separated.

A 3 meter Q column elutes Hydrogen at 0.53min and nitrogen at 0.60min. They are barely separated.

Unfortunately I do not have the conditions saved, and I do not believe that helium was well separated.

Send me your email if you want me to send you the chromatogram.

best wishes,

Rod
chromatographer1 at aol

[YDY]

Thank you for your help. I tried below conditions:
Oven T= 35 degrees C and 60 degrees C
Detector T=150 degrees C
Inlet T= 60 degrees C
Flow= 15 mL/ min and 35 mL/min
Ibnjection volume = 50 microlitre and 250 microlitre
but in each case there is tailing in the peak, at the end of the there are wave kind of behavior.
The gas sample I am testing is 100 % H2, do you have any recommendation to solve this problem?

Thanks a lot

[chromatographer1]

Sounds like a column with voids (old overheated packing, or made that way originally, a common problem).

What flow is your reference TCD?

Are you using a hot wire detector, a thermister, or Agilent's TCD which does not use a reference per se

Make sure you have the right gas parameters (choice of gas and polarity of electrometer) keyed into your GC.

best wishes,

Rod

[AICMM]

YDY,

How much are you shooting and do you have control over the filament temperatures?
For 100% hydrogen, you probably do not need to shoot very much (even with a TCD considering you are using N2 Carrier) and you can run a fairly cool filament.

Best regards,

AICMM

[YDY]

Hi,

I reduced the column flow to 10 mL/min and the rest are like this:

Oven T : 35 C
Detector T: 175 C
Inlet T: 150 C

Injection volume of 25 microlitre, and it works fine there is a nice peak., but when I increase the injection volume there is tailing and the peak rises normally but drops sharply and there is wave kind of behavior. Some has split at the top. I am planning to measure low amounts of hydrogen and I use %100 H2 for calibration.

Do you have any idea why I get deformed peaks with the increase in the injection volume? What can I do for that?

Thanks a lot

[chromatographer1]

I would suggest that you do not use 100% hydrogen to calibrate unless you have no other choice.

I suspect you are overloading this column. Any other choices?

The tailing is probably due from pockets or voids formed in the column, either from it initial manufacturing or later due to shrinkage of the beads due to age and heat. This is expected but some manufacturers do better than others.

The dead volume found throughout your sample flow path also causes tailing.

You have not given any details of the column parameters or how it is connected to your injector. Likewise, you have failed to give any details about your detector other than temperature settings.

No info = no more advice you cannot expect people to read your mind if you want good advice.

good luck,

Rod