113-3133 Chromatography Column Peak Separation and Detection of Products

Hi Raina,

without knowing the conditions/method and expected components I can only give limited advise, but you can check our application notes below:

• S2: https://www.agilent.com/cs/library/chromatograms/s2.pdf
• S1: https://www.agilent.com/cs/library/chromatograms/s1.pdf
• C776: https://www.agilent.com/cs/library/chromatograms/C776.pdf
• C605: https://www.agilent.com/cs/library/chromatograms/c605.pdf
• C603: https://www.agilent.com/cs/library/chromatograms/C603.pdf
• 113-3133: https://www.agilent.com/cs/library/chromatograms/113-3133.pdf

You can find these in our Application Note Search App, Scanview, too (and 6000+ more appnotes).

Regards,

Norbert

Thank you for your response. I really appreciate your help. I realized I didn't provide clear information about the experimental conditions. Here are the specific conditions:

• Inlet temperature: 250°C
• Column oven temperature: 150°C (isothermal)
• Detector: FID detector
• Detector temperature: 320°C
• Carrier gas: helium

We are looking to detect methane gas, but currently, hydrogen is causing interference.  Is there anything we can do to mitigate this issue?

And It seems that a TCD detector would be more suitable for our needs. Is it possible to replace the detector on our 6890 with a TCD?

Looking forward to your response.

Hi Raina,

on Carbon columns H₂ will be the first peak closely followed by methane. Like on all PLOT columns overloaded peak shift to smaller retention times, i. e. into your hydrogen signal. There is nothing you can do with this type of column. Hydrogen/methane separation works best on Molsieve 5A columns, but no C2+ hydrocarbons or water or CO₂ are allowed on that phase, therefore you use column switching with a PoraPLOT Q pre-column and switch the very first peak (composite of H₂, CO, O₂, N₂, CH₄) onto the Molsieve column for detailed analysis. That is the most robust analysis.

You can also use a Select for Permanent Gases column to do it, This is a column with 2 parallel connected columns, some application examples are here:

• A02050: https://www.agilent.com/cs/library/applications/A02050.pdf 
• A02032: https://www.agilent.com/cs/library/applications/A02032.pdf 
• A02031: https://www.agilent.com/cs/library/applications/A02031.pdf 
• A02030: https://www.agilent.com/cs/library/applications/A02030.pdf 
• A02028: https://www.agilent.com/cs/library/applications/A02028.pdf 
• A02017: https://www.agilent.com/cs/library/applications/A02017.pdf 

A TCD would be the most used detector in this kind of analysis and your GC should be able to carry one. For that please contact Agilent Service.

Regards,

Norbert

Hi Raina,

on Carbon columns H₂ will be the first peak closely followed by methane. Like on all PLOT columns overloaded peak shift to smaller retention times, i. e. into your hydrogen signal. There is nothing you can do with this type of column. Hydrogen/methane separation works best on Molsieve 5A columns, but no C2+ hydrocarbons or water or CO₂ are allowed on that phase, therefore you use column switching with a PoraPLOT Q pre-column and switch the very first peak (composite of H₂, CO, O₂, N₂, CH₄) onto the Molsieve column for detailed analysis. That is the most robust analysis.

You can also use a Select for Permanent Gases column to do it, This is a column with 2 parallel connected columns, some application examples are here:

• A02050: https://www.agilent.com/cs/library/applications/A02050.pdf 
• A02032: https://www.agilent.com/cs/library/applications/A02032.pdf 
• A02031: https://www.agilent.com/cs/library/applications/A02031.pdf 
• A02030: https://www.agilent.com/cs/library/applications/A02030.pdf 
• A02028: https://www.agilent.com/cs/library/applications/A02028.pdf 
• A02017: https://www.agilent.com/cs/library/applications/A02017.pdf 

A TCD would be the most used detector in this kind of analysis and your GC should be able to carry one. For that please contact Agilent Service.

Regards,

Norbert