Pros and cons of Argon/methane versus Nitrogen in GC-ECD

[deed11]

Hi Everyone!

Can anyone guide me what are the advantages and disadvantages of using Argon/methane against Nitrogen and vice versa in GC-ECD? If anyone cite some literature...

Thanks

[Don_Hilton]

Expect better sensitivity with the argon/methane mixture because of processes like the Penning effect (http://en.wikipedia.org/wiki/Penning_ionization). See also http://en.wikipedia.org/wiki/Penning_mixture. Also expect greater cost.

The discussion of the proportional counter may also be helpful. http://en.wikipedia.org/wiki/Proportional_counter

[deed11]

Thank you very much for all that information

[AICMM]

deed11,

As Don notes, argon/methane is supposed to give you better sensitivity. Nitrogen is supposed to give more dynamic range (although ECD's don't have much dynamic range to begin with....) Which one is more important to you usually drives the choice.

Best regards.

[Ron]

ECD sensitivity is application dependent. I have seen cases in which P5 is better than nitrogen, and other cases where there is no significant difference. The only way to know if the application is better wtih P5 is to try it or find a good literature reference.