Methanizer Maintenance

[RobertNPruden]

I am working with an Agilent 7890A GC with methanizer (nickel catalyst). My 1 ppm CO/CO2 standards are generating RF's of 0.00023 whereas all other standards (10-2500 ppm CO/CO2) are generating RF's averaging 0.00044. Does anyone know if the difference between my lowest standard and the others is normal or is my methanizer not converting efficiently. Is there a way to clean the nickel catalyst to remove any contaminants such as carbon build up? One of the most problematic balance gases that I have to work with is ethylene and some methanizer contamination has occurred. Thanks in advance for any good advice.

[chromatographer1]

To remove contaminants (polymerized ethylene and sulfur compounds) which poison the catalyst you have to heat the methanizer to very high temperatures (>600°C) purging it with oxygen or air. [Doesn't always work, either]

It is much cheaper and prudent to replace or repack the methanizer with new catalyst.

best wishes,

Rodney George