analysis of hydrogen in hp plot u column.

[rohitj]

hi, is it possible to analyse hydrogen using hp plot u column, in a gc equiped with tcd. Can u specify the elution time for hydrogen.it will be very helpful if someone can provide a procedure with a chromatograph showing peaks of hydrogen using plot u column

[chromatographer1]

What carrier gas are you using?

You should be using nitrogen. Any oxygen or nitrogen impurities will not likely be detected. What gases do you seek or expect to see?

Your question lacks details of your expectations which are required unless you seek a long series of question and answer postings before you get an answer to your question.

best wishes from the frigid Kansas City with wind chills of -20.

Rod

[rohitj]

hey rod,,
Thank u for replying,
Ya the carrier gas is nitrogen,the gas sample is collected from bio reactor.
Other gases expected are methane and carbon dioxide.
Previous studies were done using plot q column or mol sieve 5ā column.but we are presently having only plot u column. I want to know whether it can be done in plot u column.
Thank you.

[chromatographer1]

For maximum sensitivity you should use helium or hydrogen as your carrier with a TCD.

But if your matrix is air primarily, that may swamp your methane peak separation.

I can see why you are using nitrogen to avoid seeing an air peak. Methane and carbon dioxide will have a poor response with nitrogen carrier. As you may have an upset with the oxygen peak in your TCD this may hide or distort the methane peak. Your CO2 should be cleanly separated. But you may not be able to detect it.

I would do your analysis with an FID, a methanizer, and hydrogen carrier to see extremely low levels of methane and CO2 with a capillary column as you seem to be using.

But you must be the final judge.

best wishes,

ROd

[AICMM]

rohitj,

Hydrogen will probably be the first peak off. It almost always is. Sensitivity with nitrogen carrier for hydrogen will be okay, sensitivity (as noted) for other peaks will not be that great.

Best regards,

AICMM