Flow In saver gas

Hi, 

Which is the correct flow in saver gas for GC/MS? I have it at 20ml/min 

Parents
  • It's not safe for your columns to set the gas saver less than 20 ml/min.   There can be back diffusion of air into the inlet and so into the liner and the column. If the inlet is hot, that oxygen can cause issues with the inertness of the liner. Columns can be damaged by as little as 50ppm oxygen.  The low inlet pressure because the column outlet is at vacuum in a mass spectrometer allow this to happen even easier. The oxygen in the column goes into the source and causes issues inside the hot MS.  20 ml/min is the safest absolute minimum and a bit higher may be a bit safer depending on other settings.   If you want to save helium there are other ways that are better than just trying to turn the flows down.

Reply
  • It's not safe for your columns to set the gas saver less than 20 ml/min.   There can be back diffusion of air into the inlet and so into the liner and the column. If the inlet is hot, that oxygen can cause issues with the inertness of the liner. Columns can be damaged by as little as 50ppm oxygen.  The low inlet pressure because the column outlet is at vacuum in a mass spectrometer allow this to happen even easier. The oxygen in the column goes into the source and causes issues inside the hot MS.  20 ml/min is the safest absolute minimum and a bit higher may be a bit safer depending on other settings.   If you want to save helium there are other ways that are better than just trying to turn the flows down.

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